List of Hey Arnold! episodes facts for kids

Arnold accidentally knocks out a tough kid named Harold during a baseball game. Harold then tells Arnold he has 24 hours before he'll get him back.

Notes: This story was later used again in a Season 1 episode called "24 Hours to Live." This pilot was also shown in movie theaters before the 1996 Nickelodeon movie Harriet the Spy.

Downtown as Fruits: Arnold and Gerald are dressed as fruits in the school play. When Helga, the director, isn't nice to them, they leave the play and ride a bus downtown.
Eugene's Bike: Arnold accidentally breaks Eugene's new bike. Arnold tries to make it up to Eugene by taking him out for a fun day, but Eugene keeps having accidents.

The List: Arnold tries to do everything on a special list for a "perfect Saturday." But his plans go wrong when there's no good cereal, the TV breaks, and a hill for skating is being fixed.
Haunted Train: On a boring night, Grandpa Phil tells Arnold and his friends a scary story about "The Haunted Train." Arnold, Gerald, and Helga get curious and go to the old train tracks to look for it.

Operation Ruthless: Helga tries to stop Arnold from liking Ruth McDougal, a sixth grader, at the city's Cheese Fair.
The Vacant Lot: Arnold and his friends clean up a dirty empty space to play baseball. But when adults find it, they take it over for their own activities.

6th Grade Girls: Two sixth-grade girls, Connie and Maria, invite Arnold and Gerald to their school dance. But the boys soon find out the girls are just using them to make their boyfriends jealous.
The Baseball: Arnold's baseball hero, Mickey Kaline, is about to stop playing. Arnold and Gerald go to Mickey's last game.

Guest Star: Ron Perlman as Mickey Kaline

Benchwarmer: Arnold and his friends play on a basketball team. Their coach, Coach Wittenburg, only tells them to pass the ball to his son, Tucker.
Cool Jerk: A cool older boy named Frankie G. becomes friends with Arnold. But Arnold soon realizes Frankie G. only wanted to be friends to get help with something illegal.

The Little Pink Book: Helga's secret diary is full of poems and drawings about Arnold. Arnold and Gerald find the diary and take it to Arnold's house to figure out whose it is. Helga must get it back before Arnold sees her name on the last page, even if it means hiding in his closet all night.
Field Trip: On a school trip to the aquarium, Arnold sees Lockjaw, an old turtle that looks sad and neglected. Arnold feels bad for it. Later that night, Arnold and Grandma sneak into the aquarium to set Lockjaw free.

Tutoring Torvald: Arnold has to help a 13-year-old bully named Torvald with his math, even though Torvald is still in fourth grade.
Gerald Comes Over: Gerald visits Arnold's boarding house and meets all the unique people who live there.

Arnold's Hat: Helga secretly takes Arnold's hat to add to her special collection – a statue of Arnold's head made from his chewed bubble gum. Arnold feels lost without his hat. Helga plans to give it back, but her mom accidentally throws it in the trash, which is headed to the dump.
Stoop Kid: While playing football, Arnold's ball lands on Stoop Kid's stoop (front steps). Gerald says Stoop Kid is a teenager who has lived on those steps his whole life. Arnold tries to get his ball back and convince Stoop Kid to finally leave his stoop.

Heat: A very hot weather wave hits the city. Arnold and Gerald try to find ways to cool down.
Snow: A big snowstorm comes to the city. Arnold's Grandpa tries to teach him about hard work while his friends are outside playing in the snow without him.

Helga's Makeover: Helga is a tomboy, so she's the only girl not invited to Rhonda's sleepover. Feeling left out, she gives herself a new look and goes anyway.
The Old Building: Arnold is caught in the middle when Grandma and Ernie argue about whether an old theater should be torn down or saved.

Mugged: After someone tries to steal from him, Arnold learns self-defense moves from his Grandma. He soon realizes his new skills are getting out of control when he accidentally hurts an innocent person.
Roughin' It: Grandpa takes Arnold and Gerald on a camping trip. Big Bob, Helga, and Phoebe show up in a fancy RV to camp too. Everyone gets lost while hiking, and Arnold and Gerald use Grandpa's survival tips to find their way back.

Door #16: Arnold is given a package for the mysterious Mr. Smith. All the people in the boarding house are curious about what's inside. Arnold and Gerald try to deliver it safely while searching the city for Mr. Smith.
Arnold as Cupid: Oskar is kicked out of his room after arguing with Suzie about money. He tries to find a new place to sleep and ends up in Arnold's room. Arnold gets tired of Oskar's habits and tries to help Oskar and Suzie get back together.

Das (The) Subway: Arnold and his friends have trouble while riding the subway.
Wheezin' Ed: Arnold and his friends travel to Elk Island to find pirate treasure. The treasure is said to be haunted by a gangster with a breathing problem.

Spelling Bee: Arnold competes in a big spelling bee to win money for a keyboard. He competes against Helga, whose father really wants her to win.
Pigeon Man: Arnold meets a man who lives with pigeons and doesn't trust other people. When Arnold's pigeon gets sick, the man helps. Arnold tries to show the Pigeon Man that people can be trusted, but some kids cause trouble.

Guest Star: Vincent Schiavelli as Pigeon Man

Olga Comes Home: Helga is jealous of her smart, talented older sister, Olga, who is home from college. Helga secretly changes one of Olga's grades, which makes Olga very sad.
Sally's Comet: Arnold and Gerald send in cereal box tops to get a telescope so they can see Sally's Comet. But the city lights are too bright. They try to convince everyone to turn off their lights.

Abner, Come Home!: Arnold's pet pig, Abner, chases a cat and runs far away from home. Arnold organizes a search party to find Abner.
The Sewer King: Arnold accidentally drops his Grandpa's golden watch into the sewer. Arnold and Gerald go into the sewer to get it back and find it's held by the mysterious Sewer King.

Magic Show: Arnold picks Helga for his magic disappearing act. Helga tries to trick Arnold, but she accidentally knocks herself out and dreams of a world where no one misses her.
24 Hours to Live: This episode is a remake of the pilot. Arnold accidentally knocks Harold out during a baseball game, and Harold gives Arnold 24 hours before he'll get him back.

Arnold tries to find Mr. Hyunh's daughter, who was separated from him during the Vietnam War. Arnold is Mr. Hyunh's Secret Santa. The only person who can help them agrees, but only if Arnold and Gerald do all his Christmas shopping. Meanwhile, Helga has to choose between a Christmas present for herself (Nancy Spumoni boots) and a perfect gift for Arnold.

False Alarm: Eugene is blamed for pulling the fire alarm at school. Arnold questions his friends in a pretend courtroom to find out who really did it.
World Records: Arnold and his friends try to break world records to get into the Guinness Book of Records.

On Valentine's Day, Arnold has two dates: one with Ruth, a sixth grader he likes, and one with his French penpal Cecile (who is actually Helga in disguise). But then the real Cecile shows up, and Arnold realizes Ruth isn't who he thought she was.

Save the Tree: Arnold and his friends must stop Big Bob from cutting down the oldest tree in town.
New Teacher: The kids make their new teacher, Mr. Simmons, quit. The replacement teacher makes them realize how much they liked Mr. Simmons.

Note: This is the first time Mr. Simmons appears in the show.

Helga's Love Potion: Helga drinks a special drink to try and stop having feelings for Arnold.
Gerald's Secret: Gerald's secret is revealed: he doesn't know how to ride a bike. Arnold tries to teach him.

The Big Scoop: Arnold and Gerald compete with Helga in the school newspaper. They find out Helga is making up stories. When one of her fake stories scares everyone, Arnold and Gerald show the truth.
Harold's Kitty: Arnold and Harold rescue a kitten they think is lost. Harold becomes very attached to the kitten, named Cupcake. But the kitten belongs to a grumpy old lady, and Harold refuses to give it back.

Longest Monday: On the first Monday of June, fifth graders traditionally throw fourth graders into trash cans. Arnold and Gerald try to avoid this, but it's harder than they thought.
Eugene's Pet: Arnold accidentally kills Eugene's fish with a yo-yo. Arnold tries to make it up to Eugene.

Monkey Business: An organ grinder's monkey kisses Helga. Helga becomes convinced she has a monkey-related illness.
Big Caesar: Arnold and Gerald go fishing, determined to catch the pond's biggest fish, the legendary "Big Caesar."

Ransom: Gerald and Arnold investigate when Timberly's doll goes missing.
Ms. Perfect: Lila, the new girl, is very popular and seems perfect, which makes Helga and the other girls dislike her. The girls play a trick on Lila, but then they feel bad when they see how upset she is and learn her dad has been out of work.

Note: This is the first time Lila appears in the show.

This episode is like a funny version of the famous radio show "The War of the Worlds." The whole city thinks a Halloween prank by Arnold and Gerald is a real alien invasion.

Arnold Saves Sid: Arnold saves Sid from getting hurt. Sid then feels like he owes Arnold and tries to repay him with endless kindness.
Hookey: Arnold and Gerald skip school, but their day is ruined because they're afraid of getting caught.

Freeze Frame: Arnold and Gerald follow a mysterious man named "Porkpie" who was caught on film. They think he's planning to hurt "Marty," who turns out to be Mr. Green.
Phoebe Cheats: Phoebe copies a poem from a book for a poetry contest and wins. She feels guilty, and the trophy she won seems to haunt her until she confesses.

Mudbowl: Wolfgang and his fifth-grade friends challenge Arnold and his friends to a football game. Arnold has to convince his team that his plays will help them win.
Gerald Moves Out: Gerald gets tired of his family bothering him and moves into Arnold's boarding house. He soon realizes that living on his own isn't as great as he thought.

The High Life: Gerald starts a business selling watches, but soon too many people are selling them.
Best Friends: Rhonda and Nadine have a big fight while working on a school project. Arnold tries to help the two best friends become friends again.

Steely Phil: Arnold's Grandpa enters a Chinese Checkers tournament to win back his pride from forty years ago. The name Robby Fisher is a funny reference to the famous chess player Bobby Fischer.
Quantity Time: Helga's mother tries to get Helga and her father, Bob, to spend time together during Helga's spring break. Miriam leaves for a trip, leaving Bob and Helga alone. Bob realizes he doesn't know much about his daughter.

Eating Contest: Arnold enters a food eating contest.
Rhonda's Glasses: Rhonda gets glasses and finds out what it's like to be called a "geek," like the people she used to make fun of.

Helga's Boyfriend: Helga pretends Stinky is her boyfriend to try and make Arnold jealous.
Crush on Teacher: Arnold develops a crush on Miss Felter, a substitute teacher. He thinks she likes him back and invites him to dinner, but he later finds out she invited her fiancé, who is also named Arnold.

Guest Star: Julia Louis-Dreyfuss as Miss Felter

Hall Monitor: Phoebe becomes hall monitor and asks Helga for advice. She gets too much power, and soon everyone wants the old Phoebe back, even Helga.
Harold's Bar Mitzvah: Harold runs away from his Bar Mitzvah, thinking it will keep him from growing up.

Guest Star: Elliott Gould as Rabbi Goldberg

Coach Wittenberg: Arnold and his friends get Coach Wittenberg to be their new bowling coach. But he just yells and makes them do push-ups. They learn that Helga's bowling team is coached by Tish Wittenberg, Coach Wittenberg's ex-wife.
Four-Eyed Jack: The ghost of a former boarding house resident is believed to be causing strange things to happen. Arnold and Gerald find old glasses that might have belonged to him.

Eugene Goes Bad: Eugene finds out his hero is a rude actor, so Eugene decides to try being bad himself.
What's Opera, Arnold?: Helga and Arnold fall asleep during a field trip to the opera house. They have a dream that's a funny version of the opera Carmen.

Tour de Pond: Arnold and a descendant of his grandpa's old rival, Rex Smythe-Higgins, compete in a boat race.
Teachers Strike: Teachers at Arnold's school go on strike because they don't have enough money. Arnold and his friends are happy at first, but then they find out that every missed school day will be taken from their summer vacation. Also, their teachers start working at their favorite hangouts, making fun places feel like school.

Runaway Float: Arnold creates a great idea for a parade float and is sure it will be in the parade.
Partners: A lounge singer moves into the Sunset Arms boarding house after arguing with his songwriter, who also moves in.

Guest Star: Harvey Korman as Don Reynolds

Helga Blabs It All: Helga leaves a message on Arnold's answering machine, telling him she loves him. She then realizes she has to get to Arnold's house and delete the message before anyone else hears it, facing many challenges along the way.
Harold the Butcher: As punishment for taking a ham from a store, Harold has to work for Mr. Green at his butcher shop for a week. At first, he makes mistakes and annoys Mr. Green. But after his punishment is over, Harold realizes he actually likes working there and doesn't want to stop. Mr. Green eventually realizes Harold's help is useful.

Dangerous Lumber: Arnold has a very powerful baseball bat swing, which accidentally knocks out other players. He decides he won't play baseball anymore, just days before a big game against the fifth graders.
Mr. Hyunh Goes Country: Mr. Hyunh is a talented country singer. Arnold and Gerald record a CD with him and become his managers, making him a big star. But Mr. Hyunh doesn't like being famous. He has to decide if he wants to be world-famous or not.

Guest Star: Ron Perlman as Mickey Kaline, Randy Travis as Mr. Hyunh's singing voice / Travis Randall

Casa Paradiso: Grandpa Phil gets annoyed and decides to sell the boarding house to move into a condo. Arnold and the other boarders try to make him change his mind.
Gerald's Tonsils: Gerald's voice gets much deeper after he has his tonsils removed, just a few days before the school recital.

Note: Gerald's voice changed because his voice actor was growing up.

Arnold's Room: Sid pretends that Arnold's room is his own when he studies with Lorenzo, a rich classmate.
Helga vs. Big Patty: Big Patty, a tough sixth-grade girl, challenges Helga to a fight after Helga makes too many jokes about her.

Stinky Goes Hollywood: Stinky becomes the new face for Yahoo Soda, but he quits when he finds out he was hired as a joke. His parents are upset because they only care about the money.
Olga Gets Engaged: Olga gets engaged to a man named Doug who tricks people. Helga doesn't like him, but she thinks about letting the marriage happen so Olga can be unhappy. Arnold convinces her to stop it, and Helga tries to break them up.

Curly Snaps: Curly locks himself in the principal's office because he was skipped over for the job of Ball Monitor, who collects kickballs after recess.
Preteen Scream: Phoebe wins a chance to meet her favorite singer. But she finds out he doesn't write his own songs and is very self-centered.

Guest Star: Bronson Pinchot as Ronnie Matthews

Grandpa's Birthday: Grandpa thinks he's going to die when he turns 81 because of a "family curse" – every family member before him died at 81. He and Arnold spend the day before his birthday doing all the things Grandpa always wanted to do.
Road Trip: Bob has to go to a business meeting, so Miriam and Helga have to go on a family road trip by themselves to see Helga's grandmother. Miriam loses her purse and directions and ends up crashing the car.

Sid's Revenge: Sid makes a voodoo doll of Principal Wartz and believes he killed him after getting detention for a prank he didn't do.
Roller Coaster: A roller coaster breaks down while Eugene "The Jinx" and Arnold are at the very top.

The Aptitude Test: Helga thinks she's not smart because she failed a school test. She later finds out she got Harold's test score, and he got hers.
Oskar Gets a Job: Oskar gets a job delivering newspapers to earn money. But he uses Arnold to cover for his laziness, making excuses for why he can't do his job.

Arnold Betrays Iggy: Arnold finds out Iggy wears bunny pajamas when he delivers his homework. Iggy makes Arnold promise not to tell. The next day, Sid and Stinky guess the secret, testing Arnold and Iggy's friendship.
Helga and the Nanny: Bob hires a nanny named Inga to help Miriam and take care of Helga while Miriam does community service. Helga doesn't like Inga and tries to get her fired.

Career Day: Arnold is paired with the grumpy Jolly Olly Man for Career Day. The other kids think it's the best job because he's around ice cream all day. Arnold helps the Jolly Olly man be nicer to his customers and please his boss, who is also grumpy.
Hey Harold!: Harold is invited to Rhonda's party but doesn't want to go because he thinks no one will dance with him. At the party, he dances with and becomes friends with the tough girl, Big Patty. They spend the next day together, but Stinky and Sid tease Harold about it.

Best Man: Coach Wittenberg asks Arnold to be the best man at his second wedding to his ex-wife, Tish Wittenberg. Helga is asked to be the maid of honor.
Cool Party: Rhonda throws a party only for "cool" people at her house. In response, Arnold and his friends have a "geek" party on the roof of his boarding house. Rhonda's party becomes empty because it's boring and only about her.

Arnold & Lila: Arnold gets more attention than he wanted from Lila after Helga writes "Arnold Loves Lila" on a wall. Helga had first written "Arnold Loves Helga," making the other girls think Arnold wrote it.
Grand Prix: The kids compete in a go-kart race against each other.

Arnold and Helga are tired of their families' Thanksgiving traditions. Arnold's grandma mixes up Thanksgiving and Fourth of July, so his meal is hotdogs and fireworks. Helga is upset because her family ignores her, even on Thanksgiving. They both leave and go to Mr. Simmons' house, but then they realize their own family Thanksgivings aren't so bad after all.

Helga's Show: Helga tells jokes about her classmates, which makes them upset.
The Flood: The town is flooded, and Arnold's class gets trapped in the school.

Phoebe Takes the Fall: Helga tells Phoebe to lose a quiz competition to impress Helga's competitive father.
The Pig War: Arnold, Grandpa, and friends act out the Pig War.

Note: "The Pig War" was inspired by a real conflict in Washington state in 1859.

Part-Time Friends: Arnold is okay working with Gerald at Mrs. Vitello's flower shop, but not for Gerald when Gerald is put in charge. This causes problems in their friendship, and Arnold quits.
Biosquare: For a science project, Arnold and Helga have to work together and get along for 24 hours in the Sunset Arms greenhouse when they get locked inside.

Crabby Author: Arnold does a school report on an author he likes, but then finds out she's a very grumpy old lady.
Rich Kid: Lorenzo, a nervous rich kid, comes to P.S. 118. All the kids try to help him become a more normal kid.

Guest Star: Rose Marie as Agatha Caulfield

Girl Trouble: Arnold gets fed up with Helga bothering him and pours paint on her after she pours some on him. He learns that Grandpa had a girl bully when he was young, much like Helga (and it turns out to be his wife, Gertie).
School Dance: Arnold is in charge of the school dance. He books an old singer named Dino Spumoni. When Dino sings a sad "good-bye" song, everyone blames Arnold.

After hearing that Arnold is playing Romeo in the school play of Romeo and Juliet, Helga does everything she can to get the part of Juliet so she can kiss him. She scares the other girls who have the role before her.

Full Moon: Arnold is blamed for something he didn't do.
Student Teacher: Helga's sister Olga comes home for spring break and becomes a helper in Helga's class, which Helga really doesn't like.

Big Gino: Sid pays off a debt to a tough kid named Big Gino, and they become friends. But when Sid is told to play a mean trick on Arnold, he has to choose between his new friend and Arnold.
Jamie O in Love: Gerald's older brother Jamie O suddenly becomes very kind when he finds a girlfriend. But Arnold and Gerald soon find out that the girl is just using Jamie O. Gerald isn't sure if he should tell his brother the truth, which might make Jamie O go back to being mean.

Eugene's Birthday: Arnold loses Eugene's birthday party invitations, so he feels he has to throw Eugene another party, but it doesn't go well.
Stinky's Pumpkin: Stinky grows a huge pumpkin for a city competition to prove he's good at something, even though his family says nothing has grown on their land for years.

The Beeper Queen: After Bob gets hurt, Miriam takes over running Big Bob's Beepers. At first, she becomes a very caring mom, but she soon gets too busy and forgets about her family. Helga has to help her realize what's important.
Oskar Can't Read?: Arnold finds out that Oskar can't read and tries to teach him. The final test is for Oskar to find his way home across town using only a map and written directions.

Dinner for Four: Helga wants to show Arnold she can be as fancy as Lila. She takes him, Gerald, and Phoebe out to dinner with a coupon she won. She plans to avoid paying when she realizes they're at the wrong restaurant.
Phoebe Skips: Phoebe is moved up to the sixth grade. She ignores Helga when Helga tells her that her new "friends" are just using her to do their homework. Phoebe learns this the hard way when a younger girl also moves up to sixth grade, and her "friends" leave Phoebe for the new girl. Phoebe cries to Helga, who welcomes her back and plans to get back at the older girls.

Helga's Parrot: Helga talks in her sleep and tells Bob's parrot about her love for Arnold. The next day, the parrot flies into Arnold's window, and Helga has to get it back before Arnold hears her secret.
Chocolate Turtles: There's a problem when Gerald's little sister, Timberly, eats all the chocolate turtles that he and Arnold are supposed to sell for a scout group.

Love and Cheese: Helga tries to keep Arnold and Lila apart at the annual Cheese Fair.
Weighing Harold: Harold thinks his friends believe he's overweight, so he decides to go on a special trip to lose weight. But when he comes back, he's even bigger.

Back to School: Grandpa tells Arnold he never got his grade school diploma. Arnold convinces him to go back to school at P.S. 118.
Egg Story: Arnold and Helga have to take care of an egg for a school project about being parents. Meanwhile, Rhonda and Harold are partners and also have to take care of an egg.

It Girl: Helga becomes a model, but she quits when everyone starts dressing like her, which annoys her.
Deconstructing Arnold: Arnold's classmates are tired of him always telling them the right thing to do, so he stops giving advice. But then, when they get into tricky situations, they really need his help.

Guest Star: Michael McKean as Johnny Stitches

Grudge Match: After a car accident, Big Bob and Grandpa Phil have a golf match. The loser has to pay for the damage to both cars.
Polishing Rhonda: Rhonda goes to a special school to learn manners after a fight with Big Patty. But she's not very good because of her bad attitude. She realizes her money won't help and asks Big Patty, who is doing very well at the school, for help.

Weird Cousin: Arnold's quiet country cousin, Arnie, comes to visit. Lila immediately likes him, and they start spending time together, making Arnold a little jealous. Arnie, however, is interested in Helga.
Baby Oskar: Oskar has to take care of his baby cousin (also named Oskar) while the baby's mother is away. He complains that the baby gets all of Suzie's attention. When Suzie has to go to work, Oskar is in charge. He starts to bond with the baby and takes action when the baby seems sick.

Grandpa's Sister: Phil's twin sister, Mitzi (voiced by Phyllis Diller), comes to visit, bringing up an old argument between them.
Synchronized Swimming: Arnold and his friends are part of a synchronized swimming team led by Coach Wittenburg.

Helga Sleepwalks: After eating pork rinds, Helga talks in her sleep and reveals her secret about Arnold.
Fighting Families: Arnold, Grandpa, Grandma, Ernie, and Mr. Hyunh compete on a game show against a "perfect" family from another school.

Guest Star: Ryan Seacrest as the Fighting Families Host.

Headless Cabbie: Arnold tells a scary story about a taxi driver without a head. The friends go out, and the details from the story start to seem real.
Friday the 13th: Arnold and Gerald try to prove that superstitions aren't real, but everything goes wrong for them.

Arnold's Grandpa tells stories about his time as a soldier in World War II, and Gerald's dad, Martin, remembers his time serving in Vietnam. Gerald thinks his dad isn't a real hero because he was just a file clerk. Arnold thinks Grandpa is making up stories. But both boys learn they are wrong when Arnold sees a statue for his grandpa, and a visitor from Martin's past shows up.

A child therapist, Dr. Bliss, observes students at P.S. 118 and notices Helga's behavior, especially towards Arnold. After Helga punches Brainy, she has an appointment with Dr. Bliss. Helga tells Dr. Bliss about her social life, family life, and her secret love for Arnold.

Guest Star: Kathy Baker as Dr. Bliss

The singer Dino Spumoni is reported missing and then declared dead. But Arnold finds out that Dino is secretly living in the boarding house, believing that his music will become more valuable after his "death."

Monkeyman!: Arnold helps the superhero Monkeyman try a normal life. But Monkeyman becomes too busy to help people in need. He realizes his mistake after Sid is robbed in front of a big party Monkeyman is attending.
Buses, Bikes, and Subways: Helga and Harold have to find their way back to town on their own after the bus leaves them behind after a school trip to a chocolate factory. Helga has tickets for a wrestling match and can't be late.

Guest Star: Andy Dick as Monkey Man

Helga's Masquerade: Helga decides to act like Lila at Rhonda's costume party so Arnold will like her.
Mr. Green Runs: Mr. Green runs for city council after his requests to fix a large pothole in front of his store are ignored. Arnold becomes his campaign manager, but can a butcher win against a politician?

Sid the Vampire Slayer: Sid thinks Stinky is a vampire.
Big Sis: Olga joins a "Big Sis" program, and her "Lil' Sis" turns out to be Lila.

Bag of Money: Arnold, Sid, and Gerald find a bag full of money, but they don't know what to do with it. Arnold is chosen to hold onto it. However, when Arnold accidentally loses the money, his friends start to think he stole it, and he has to prove he's innocent.
Principal Simmons: Mr. Simmons is upset that Principal Wartz is too strict. Wartz decides to quit and chooses Mr. Simmons to take his place. The new Principal Simmons makes big changes to make the school more relaxed, but will the students like his new rules?

New Bully on the Block: The kids face two older bullies when a new kid, Ludwig, returns and challenges Wolfgang for the empty lot.
Phoebe Breaks a Leg: Phoebe breaks her leg after being hit by a bus. Helga thinks it's her fault, so she starts being very nice to Phoebe. When Phoebe's leg heals, she pretends to still be hurt to keep Helga being nice.

Helga's Locket: Helga carves her name into her locket that has Arnold's picture. Arnold's grandpa finds Helga's locket and thinks it's an anniversary gift from Grandma. Helga must find a way to get it back before Arnold finds out her secret.
Sid and Germs: Sid becomes obsessed with being clean after watching a film about germs. His new obsession ruins the fourth graders' chances in a frog-catching contest against the fifth graders.

Suspended: Harold gets suspended from school and will do anything to get back once he realizes being home all day isn't fun.
Ernie in Love: Ernie gets a crush on a tall, kind model named Lola. Arnold helps him find the courage to ask her on a date. She accepts, but after the date, she's not sure about another one because of Ernie's height.

Guest Star: Jennifer Tilly as Lola

Parents' Day: It's time for the school's "Parents' Day," a weekend of competitions for kids and their parents. Arnold feels strange bringing his grandparents, as he hasn't seen his real parents since he was a baby. After Big Bob calls Arnold an "orphan boy," Arnold asks Grandpa Phil what happened to his parents. He finds out they disappeared after leaving the country on a plane to deliver medicine. Arnold continues with Parents' Day with Phil and Gertie, realizing that even though they aren't his birth parents, they raised him and made him who he is.

Summer Love (a.k.a. Beach Story): Arnold, the boarders, and the Patakis go to the beach. A girl uses Arnold to win a sandcastle competition. Ernie gets buried in the sand. Miriam and Suzie take dancing lessons. Grandpa Phil thinks he's stuck on an island. Oskar uses a metal detector to find "treasure." Big Bob gets a bad sunburn. Helga tries to warn Arnold that he's being used.

Guest Star: Beverly Mitchell as Summer

Stuck in a Tree: Arnold gets stuck in a tree with Harold and Eugene.
Rhonda Goes Broke: Rhonda's family loses all their money, and they have to move into the boarding house.

Beaned: Helga gets hit by a baseball during a game and loses her memory. Arnold feels responsible and stays with her all day. The next day, Helga gets her memory back, but she pretends to still have amnesia to spend more time with Arnold.
Old Iron Man: Grandpa Phil and his old friend, Jimmy Kafka, have been arguing for years. They decide to compete in a very tough triathlon. Arnold tries to stop their argument because he doesn't want them to risk their lives over something so small.

Guest Star: Richard Mulligan as Jimmy Kafka

Arnold Visits Arnie: Arnold visits his cousin, Arnie, whose friends look a lot like Arnold's friends. Arnie's flirty girlfriend, Lulu (who looks like Lila), is very interested in Arnold, while Arnold likes a kind girl named Hilda (who looks like Helga), who likes Arnie.
Chocolate Boy: After winning a bet against Wolfgang, Chocolate Boy wants to stop eating chocolate. Arnold helps him, realizing that chocolate is how Chocolate Boy copes with his nanny leaving him a long time ago.

Harold vs. Patty: P.S. 118 is having an arm wrestling contest. Harold is embarrassed when he loses to Patty before the contest, so he asks Patty for tips on how to win.
Rich Guy: Arnold saves a rich man's life, and the man invites Arnold and Grandpa Phil to his house. He tells Arnold he wishes Arnold was the son he never had, but he actually has a son they don't get along with.

Guest Star: Fred Willard as Sammy Redmond

April Fool's Day: Arnold is tired of everyone playing April Fools' jokes on him, especially Helga. So he tries one of his own, but it goes wrong and temporarily makes Helga unable to see.

Gerald's Game: Gerald gets very involved in his new favorite game, which Arnold doesn't like.
Fishing Trip: Arnold, Gerald, Harold, Sid, and Eugene go on a fishing trip with their fathers and Phil.

Guest Star: Davy Jones as himself

Married: Rhonda uses a paper fortune teller to see who will marry whom. Arnold and Helga are paired up, causing them both to dream about what life would be like married to each other. Helga dreams of a wonderful life, becoming president with Arnold by her side. Arnold has a nightmare, dreaming of being overworked while Helga does nothing to help with the house or their future children, and she's still mean to him.

On the Lam: Stinky, Harold, and Sid run away because they think they blew up the police station.
Family Man: Mr. Hyunh has Arnold pretend to be his son, Suzie his wife, and Phil and Gertie his parents for his new boss. He does this to get a promotion, as his boss loves families. Mr. Hyunh doesn't want to reveal he only has his daughter and lose the promotion.

The Racing Mule: Mr. Hyunh, Oskar, and Ernie buy a racehorse, or so they think.
Curly's Girl: Curly gets Rhonda to pretend to be his girlfriend after she spills caramel on her mother's birthday present – a fur coat – that she wore to a party without permission. He offers to fix it at his parents' dry-cleaners if she publicly acts like his girlfriend for one week.

The Journal: Arnold finds a journal that describes his parents' adventures in the jungle, their marriage, Arnold's birth, and other details of their lives. The last page has a map showing where they went after they left him to deliver medicine to people in the jungle.

Note: This was the last episode made and was meant to lead into "Hey Arnold!: The Jungle Movie".

Timberly Loves Arnold: Arnold lets Timberly join him and Gerald when they play ball. Timberly develops a crush on Arnold, which makes Lila start to like Arnold too because he's helping Timberly.
Eugene, Eugene!: Eugene gets the main role in the school musical "Eugene, Eugene." But the play director changes the ending, where Eugene's character is killed off instead of getting the girl and being a hero. The most popular song is removed, and a song is given to the villain (played by Arnold).

Ghost Bride: Gerald tells a scary story about the Ghost Bride, Cynthia Snell.
Gerald vs. Jamie O: Gerald gets jealous because he thinks Jamie O. is trying to steal the girl he likes. But actually, the girl likes Jamie O and is just using Gerald to get closer to him.

A Day in the Life of a Classroom: Mr. Simmons wins an award, and a TV station makes a documentary about how he teaches.
Big Bob's Crisis: After Big Bob thinks he had a serious health problem (it turns out to be gas), he tries to become a nicer person. He takes it too far, building a hut to meditate in, selling everything they own, and trying to get Miriam and Olga to join his new lifestyle. Things get worse when Bob says they're selling the house and moving to a community in Oregon. Helga has to convince him to go back to being the dad she knew.

Phoebe's Little Problem: Phoebe is embarrassed after she accidentally makes a loud noise into a microphone in front of a huge audience.
Grandpa's Packard: Grandpa's special old car, a Packard, is stolen from an antique car show.

Arnold, Gerald, and Helga try to save their neighborhood from a bad businessman named Scheck. He wants to tear down their homes to build a shopping mall.

Arnold's class wins a field trip to San Lorenzo, which is where his missing parents were last seen. Arnold uses this chance to find answers and discover what happened to them.