When Zack and Cody want to make friends, they meet Max and Tapeworm. After the 'Drew Crew' finds out where they live, they suddenly want to hang out with the twins. London needs to higher her grades so Moseby hires Maddie to tutor her. In the meantime, Maddie develops a crush on Lance the lifeguard and asks London for advice on how to be mean because he is obsessed with water.
Zack and Cody want new bikes but can't afford them. A beauty pageant comes to the Tipton and Cody accidentally is put in it. Zack takes advantage of this and convinces him to stay in so they could use the prize money. Cody crushes on a pageant contestant, Rebecca, and wants her to win.
Moseby won't let London go out with her friends because of an article about her in the newspaper, but Moseby lets London go out with her friends because Maddy is going. Maddie and Jason find they have a lot in common with each other and start to like each other. Maddie needs Zack and Cody's help to fool Jason into thinking that she is rich.
Zach and Cody have been spending way too much money which causes them to get grounded. But when they learn a celebrity couple are holding their wedding at the Tipton and that if someone can get a picture of the kiss they get $20,000.00, Zach and Cody will have to use their sly ways to sneak in and get the picture to pay off their moms bill. Will they succeed?
Carrie receives anonymous flowers with a beautiful poem outside her door. She thinks they were sent by the concierge, but Zack and Cody don't think that he is telling their mother the truth. They set out to find their mother's real secret admirer.
Zack and Max enter a dance competition, making Cody feel that Zack is better than him at everything. When Zack hurts his ankle by jumping on the bed, Cody has to step in for him, learning to appreciate his own abilities. London lends Maddie money for her parents, but then uses Maddie's indebtedness to exploit her ruthlessly.
Maddie gets her prom to be at the Tipton after London convinces Mr. Moseby. Maddie also wants someone special to ask her to the dance. Zack, thinking that he is the one that Maddie wants to take her to the prom, shows up to the prom in a tux.
Zack and Cody enter the Battle of the Bands that is held at the Tipton. Zack and Cody have some differences about their band, so they break up the band. Once it comes down to it, they realize that they work better together that apart.
Estebon is accused of stealing from one of the guests at the Tipton, but Zack and Cody think that he is innocent. So, they set out to prove that he is innocent. London goes away on vacation, but cannot bring Ivana with her, so she had Maddie watch her. Maddie and Ivana bond, and Ivana is angry with London for leaving her.
London's father loses his fortune, so he must sell all of London's expensive things. London must move into Maddie's house until her father can find a place for her to stay. London learns what it is like to be poor, and appreciates a life that she's never had to experience.
London falls for the son of her father's enemy, who owns the St. Mark Hotel. They sneak around so they can be together and Maddie helps them. Zack takes advantage of Cody's ability to bake amazing cookies to make some money.
After London starts and rumor about Maddie dating the lifeguard, Maddie unintentionally starts a rumor about London wearing real fox fur. Cody decides that he wants to be separated from Zack and experiments with his look, but it ends up getting him into trouble when the interviewer for a contest that he entered shows up.
Mr. Moseby takes the twins to a baseball game so Carrie can get a day off, but he becomes the most hated man in Boston because he cost the Red Sox the game when he catches a ball for Cody. London sets Maddie on a date with one of her friends, but Maddie's hair will not cooperate.
When Zack and Cody's father arrives in town with his band, Zack decides that his dad is a lot more fun to be with than his mom, causing him to run away by stowing away on his dad's touring bus. Meanwhile, the boys' mom tries to make restitution for driving Zack away by forcing Cody to have non-stop fun with her.
It's Christmas. Everybody gets snowed in the hotel while a pregnant Mexican woman and her husband stays there. As there is no way for the hotel to receive any oil, Arwin has to do what he can to keep everybody warm.
Max impulsively kisses Zack after a basketball victory, causing them both to question their relationship, and the team to urge him to ask her out on a date. Maddie tries to curb London's compulsive shopping habits.
Inspired by a motivational speaker who emphasizes to people to "Be the pilot of your own life", Cody sets out on a mission to get his friends and family to pilot their own lives, throwing everyone into turmoil and chaos. Meanwhile, Maddie and London compete--no holds barred--for a Trendy Teen title.
To impress a cute academically-minded boy, London tries to pass herself off as brainy with help from Maddie. Meanwhile, neatnik Cody moves out of the room he shares with sloppy Zack and transforms a closet into his very own bachelor pad.
The French Ambassador is staying at the hotel with his daughter, Jolie. Zack and Cody both want to win her affection. Cody wins. In the end, Bob gets her though. Esteban is upset because in the process of trying to save London from a Bag stealer, he gets beat up and London knocks the bag stealer unconscious. Without telling Esteban, London and Maddie plan to set it up again using Arwin.
The Tipton's chef walks out (again), leaving a more-than-willing Cody to do all the cooking. Unfortunately, he, and his personal crew, must prepare a spectacular meal for a restaurant critic who isn't what he appears to be (literally).
Zack and Cody beg their mom for a pet, so she gives them rocks. They hear that the horse man for the Tipton is retiring. Mr. Moseby is planning to sell Tippy the Horse to a "nice" man from Vermont. The twins overhear the man on his cell phone saying that he is using Tippy as a workhorse. The twins hide Tippy in Arwin's shack, but he gets loose in the hotel. Moseby makes the twins find Tippy before he does or their mom is fired. They find Tippy and let him sleep in their room for the night...BIG MISTAKE!
When Zack and Cody run against each other for class president, they find out who their friends (who have to be bribed to vote) really are. Maddie acts as Cody's campaign manager while London teams up with Zack. Since Zack's team has virtually unlimited financial resources for his campaign--while Cody tries honesty to win over votes, it's naturally a landslide in Zack's favor.
Moseby's older brother stays at the Tipton. Moseby has been ostracized by him since childhood, but soon discovers that his brother is bankrupt. Moseby tries to help him by giving him a job at the Tipton. Meanwhile Zack and Cody save their money to buy a single bike, which they must share. Zack ends up using the bike more than Cody even though Cody put up most of the money.
Cody's extracurricular activity is canceled at school, so he decides to join wood shop. Zack is also in wood shop and excels in it. Cody on the other hand does not. London and Maddy have to write a short story for school. London steals the story from Maddy and refuses to admit that she stole it.
When Maddie and London schedule their Sweet-16 parties for the same day, Maddie tries to talk London into rescheduling hers (It's not even London's birthday) for a different day, since they share the same friends. London doesn't budge. On top of that, she plans a spectacular party at the Tipton, with gifts for the guests (like plasma TVs) and great food, while Maddie, well...you know Maddie. All the guests (except Zack) show up at London's party for the free stuff, while only Zack makes it to Maddie's party ('cause we all know how much he loves her). But Maddie isn't the only one having a lousy time. London discovers that her "friends" are their just for the hand-outs, and she also must pacify her parents who aren't speaking to each other. The story does have a happy ending though.
While Cody is preparing for the Boston Spelling Bee, Zack tries to borrow money from his mom for video games. When his mom won't give him money, he borrows from everyone else in the hotel. He finally borrows $30 at 20% interest from a rather large bully. He tells Zack to pay up, "or else." After Cody and the bully become the final two contestants, the bully offers Zack another out: get Cody to lose, "or else." Zack realizes that he should let Cody do his best. It turns out, however, that the "or else" isn't being beaten up- it's having his mom find out.
The Tipton employees compete against the St. Marks' employees. They decided to play bowling. Zack is a great bowler and could lead them to victory, but he gets into some trouble and his mom kicks him off of the team. Who will come to their rescue?
"Don't play hockey in the lobby", "eat your veggies", "it's time for bed". Zack & Cody are tired of being told what to do all the time. Serendipitously, Arwin has created a Parallel Universe thingy, which the boys inadvertently use to transport themselves to a, um, parallel universe. A world of all-you-can-eat candy, all-you-can-watch-TV, and a no-rules-ever Mom. Paradise? Let's see.
Cody's been tapped to be the editor in chief for the school newspaper but when Zack begs for a position on the paper, the only job that is left for him is the advice column. Then Zack uses his position on the paper to benefit himself.
When Carey starts dating a 'New man' Cody calls his father to stop them from dating. But Kurt has other intentions with her boyfriend. London joins Maddie's volleyball team and in order for her to play well, Maddie must take drastic measures.
A wheelchair basketball team visits the Tipton and plays against Zack and Cody's team in order to raise funds for their school. Zack and Cody try to invite an old friend of theirs to join their team, who recently became a paraplegic himself after a car accident. However, his bitterness over his recent accident makes this task far more difficult than they can imagine, a fact which the coach of the other team (played by Daryl "Chill" Mitchell) knows all too well.
When Zack and Cody knock the ancient mummy over the balcony, Zack dresses Cody up to replace him for the exhibit. Esteban is scared of the curse of the mummy and he puts on garlic which smells awful! He and Maddie dress up Maddie's old doll so they can give the real mummy back to its correct place, not knowing that it's Cody.
Zach and Cody take an aptitude test. Zack's score shows he will be a succesfull CEO and Cody's score shows he will be a garbage man. So Zach starts trying to study more and become a math whiz and Cody just starts to simply not care about anything. Meanwhile, Maddie gains fame after saving the Moroccan ambassadors life. This fame causes London some jealousy.
After summer school, Zack takes a summer job working under Arwin, but finds the job so deplorable that he tries to get one at the local supermarket, even if it means working with Cody. The revelation that London can't swim, despite her on-the-side swimsuit business, forces her to take swimming lessons from Tipton lifeguard Lance, both of whom fall in love with each other. Little does she realize that the kids at Maddie's summer camp job are the ones she has to thank for this and other tabloid gossip, and even Maddie herself begins to see the benefits of their scheme.
Zack and Cody wish on a star and get super powers. Cody gets the power to read minds and move objects with his mind. Zack gets the ability to move fast. They find their arch-nemesis to be none other than Mr. Moseby, who plans to turn all children into small adults.
The manager of a rival Revolutionary War themed grocery store challenges Zack, Cody, and their boss to a speed-bagging competition. Mr. Moseby takes in his niece Nia, in order to smooth out her sassy attitude and short fuse. When it becomes clear that Maddie's replacement Millicent finds her job much too stressful, Moseby believes that a job at the candy-counter might be the perfect remedy... until she talks London into taking her to a concert and inviting the band, their crew, and their groupies over for a wild party.
The twins get grounded and are forbidden to leave the suite, leaving London's Internet show without a producer. Luckily, Maddie steps in and books Chris Brown as a guest star on the show. Meanwhile, Cody sneaks out and books some guest stars of his own, The Cheetah Girls.