Gidget Lawrence, fifteen and a half years old, falls in love with Jeff, a college student, and takes up surfing to be with him. However, Gidget's married sister, Anne, upset that her little sister is staying out all night, reads her diary and misinterprets its contents.

Gidget tells Russ she hasn't a date for Saturday's Luau and convinces her brother-in-law John to accompany her. John tries to fit in with the teenagers, but his behavior puts them off.

Gidget falls for,twenty-eight year old Cass Cobb, known as surfer legend Great Kahuna. She's even conviced Russ to invite him over. She soon finds out that Kahuna is not that interesting when not at the beach.

Convinced by his daugther Gidget to visit the beach, Russell there becomes infatuated with Sally Combs, an attractive woman in her mid-thirties. Gidget becomes alarmed by her father's interest in Sally, especially when Larue refers to Sally as a gold digger.

Anne leaves John, claiming that he is so involved in his studies that he completely ignores her. With Anne taking over her room, constantly criticizing her and tying up the phone, Gidget searches for a way to get Anne to return to John.

Determined to have her own car, Gidget signs a deal with an untrustworthy man and, much to the irritation of her father and classmates, signs up for mechanics in school.

Gidget feels that her teacher Hardy treats her tougher than the other students because she is the daughter of an English professor. She comes up with a scheme, which soon backfires.

Gidget falls for Larue's sophisticated New Yorker cousin Roger Haimes. Frustrated by Roger treating her as if she were a child, she starts acting as mature as possible.

Feeling her sister isn't ladylike enough, Anne convinces Russell to enroll Gidget in a girls' school in France. Gidget, thinking her father wants back his freedom, pretends she's fine with the decision.

When protest singer Billy Roy Soames comes to town, Gidget gets inspired by his activism. In her own twist, Gidget and Larue get Billy Roy involved in a protest to lower unfair movie ticket prices.

After Larue gets put down by a girl at the beach, Gidget decides Larue needs a make-over. Larue is more interested in an old horse that she wants to buy. Russ tries to help, and Gidget thinks her friend and her Dad are an item.

After a talk with her Dad, Gidget decides that her boyfriend, Mark, needs to learn a little chivalry. Gidget and her girlfriends all gather at her house for a pajama party to teach all their boyfriends a lesson.

A battle for a new surfing beach causes problems between Gidget and her boyfriend Brett. Gidget uses medical subterfuge to get him back from her rival Patty.

Inge, a Swedish college student, stays with the Lawrence's until the dorms open. She changes from meek to wild and steals all the boys - especially Gidget's boyfriend Mark. Gidget fumes until Inga's fiancé Gunnar shows up.

Gidget becomes the inspiration for photography student Tom Brighton. All goes well until Gidget realizes that she wants to be more than his model.

While Gidget's true love, Jeff, is away at college, Gidget enjoys herself by dating the feuding Cook cousins. She happily finds out that Jeff, is coming home for the Founder's Day dance, but then realizes she has three dates for the dance.

With Jeff back at Princeton, Gidget prepares for a lonely existence. Then she develops a crush for an older surf bum she meets at the beach. All is fine until it turns out he's her new math teacher.

After Gidget's surfboard is stolen, she is cursed by the gypsy Zangara, who is trying to sell it.

Determined to push Larue into popularity, Gidget gets her involved with Paul and Doug who are forming a singing group. Larue starts playing the guitar, but the boys only want Gidget, even if she only bangs a tambourine.

Gidget makes a date with Durf the Drag to buck up his ego. She creates an ego-driven monster and he cancels their date. Then she discovers that Russ is helping Chuck Batson (guest star Richard Dreyfuss), a gorgeous six-foot-three, to master grammar so he'll be eligible to quarterback the college team. Gidget's interest in Durf's ego drops rapidly as she schemes to get Chuck to take her to the Hop.

An invitation to meet Jef's parents is music to Gidget's ears, and the song she's hearing is the "Wedding March." However, mixed-up identities and switched sweaters cause qyite a comotion.

Gidget starts worrying when her friend, Toby, criticizes her close relationship with her father. Discussing it with Larue, Gidget concludes she might be jealous of her father's dates, but set's out to prove that she doesn't mind.

Gidget and Russ are on opposite sides of the battle to close the "Shaggy Dog," a hamburger shack and hangout for Gidget's crowd.

Gidget's rock-and-roll idols, The Dingbats, are in town on Mysterious business, and Gidget knows where they're staying. She's determined to meet them, but by the time she reaches the estate where the Dingbats are hiding, many of her friends know where they are.

While Russ is out of town, GIdget goes to a surfing tournament with her sister and brother-in-law's blessing. They don't quite trust her though and hire Scott Baker, a UCLA halfback, twenty-five dollars to watch over her.