Senior year begins but quickly turns sour when Zack and Slater clash over the new girl at school.

When the gang take part in a student-teacher exchange program, Zack becomes principal, Kelly a History teacher and Screech and Lisa the gym teachers. However, when Zack, Slater and Kelly clash over an exam, friendships are tested.

The gang produce a television show for Communications class, with the sauce Screech makes during the cookery segment proving a hit. They decide to market it, and Screech gains a girlfriend, but he refuses to believe she is using him.

A new girl, Tori, arrives at Bayside and after she takes his parking space, Zack immediately squares off against her. However, she soon develops a seemingly unrequited crush on him.

When Lisa receives word that a recruiter from FIT wants to interview her, the gang help her put on a fashion show at The Max. However, the close working conditions mean Zack and Lisa grow close, leaving Screech brokenhearted and bitter.

The gang creates a teen line, designed to help students with their problems. Zack takes a call from a girl named Melissa and asks her out, but is taken aback when they meet up and he discovers that she is in a wheelchair.

As the annual masquerade ball approaches, Zack and Slater make a bet about who can kiss Tori first. However, when she discovers their scheme, she decides to get revenge, while Screech's love letters to Lisa cause all manner of mix ups.

After rigging a radio competition, Zack has the chance to win a trip to Hawaii, but his plans are scuppered when he is sent to detention for the day and his attempts to get the gang to help result in them being sent to detention as well.

Slater is offered a wrestling scholarship at the University of Iowa, but finds it difficult to tell his father, who wants him to go to West Point.

The gang learn about the dangers of drinking and driving when, after getting drunk at a party, they get into an accident in Lisa's mother's car and try to cover it up.

Slater is horrified when his girlfriend from Germany arrives at Bayside as a new student. Zack helps hide the relationship from Jessie, but it is only a matter of time before she finds out, and Slater must figure out where his heart lies.

Zack appears to have negotiated a great deal on class rings for the senior class, but it turns out he has been scammed. While he plots revenge, a misguided bet between Tori and Lisa leads to Screech falling for Tori.

On Valentine's Day, the gang reminisce and share memories of love and past romance.

The school fights over how to spend the money that an alumni has left the school. Zack, Slater, Screech, Ox and the rest of the guys want the money for boys' sports while Lisa, Tori, Ginger and the girls want it for girl's sports. So Mr. Belding decides to settle the conflict by having a sports competition between the boys' blue team and the girls' red team. But Zack resorts to unethical tactics when he sabotages the girls' oven during the bake-off contest, and when the girls find out, they plan their revenge, leading to an all-out war between the sexes.

In order to go on a ski trip, Zack and Slater trick Mr. Tuttle into thinking Mr. Belding is against him, prompting a strike. However, their plan is so successful that it could cause the annual Academic Bowl to be canceled.

Slater is pleased when his younger sister J.B. arrives at Bayside, but his happiness is short-lived: she wants to date Zack.

As the senior prom approaches, Zack discovers he still has feelings for Kelly. However, she already has a date, and Zack resorts to skulduggery to win her hand, while romance brews elsewhere.

Zack agrees to produce Bayside's video yearbook, but betrays everyone's trust by creating a dating tape using footage of female students in order to make enough money to buy a car. When the others see the dating tape, they plot revenge.

The gang forgets Screech's birthday and decide to throw him a surprise party in Mr. Belding's office. However, after being made Hall Monitor, Screech gets his revenge by sending them to detention, jeopardizing the party.

The school puts on a hip hop version of Snow White and the Seven Dwarfs, with Zack and Jessie as the leads. However, when they seem to develop feelings for each other, they risk ruining both the play and their relationships.

To avoid a Physics test, the gang throws a baby shower for Mr. Belding's wife Becky. As they are leaving the school, an earthquake strikes, trapping Zack and Tori in the elevator with Becky, who goes into labor.

Zack, Slater, Screech and Lisa reminisce about their summer working at Malibu Sands beach club and attending Jessie's father's wedding in Palm Desert.

Slater leaves his pet chameleon, Artie, in the gang's care when he goes away for a week. However, Slater returns to find that Artie has died, and blames them.

The senior class want to leave a gift to Bayside's future students and suggest a contest to come up with a new school song. However, Zack decides to rig the competition in his favor in order to be remembered for more than just bad behavior.

In 2003, the senior class find a video time capsule buried by the gang in 1993 before graduation, and Mr. Belding, still Bayside's principal, watches it with them.

As graduation approaches, Zack learns that he is just one credit short of graduating. Desperate to get extra credit, he joins Bayside's ballet company, and when illness strikes some of the other cast members, he calls on the gang for help.