The Walsh Family moves to Beverly Hills, where the twins, Brenda and Brandon, meet new friends during their first week at West Beverly High School; Brandon falls for the most popular girl in the school while Brenda pretends to be a college student to romance a young lawyer.
Brandon meets and befriends surfer Dylan McKay, a mysterious loner who lives in a fancy hotel suite and hangs out at the beach with his surfer friends that include teenage alcoholic Betty. Meanwhile, Brenda feels she's living in poverty when she gets to know Kelly, and her insecure friend Donna Martin. Steve tries to hang out with David after mistakenly thinking that David's father is a wealthy TV show producer. Also, Andrea asks Brandon to write an article about being new in Beverly Hills.
Brenda shops with Kelly and Tiffany and wishes she had their kind of money. But Tiffany is a shoplifter and, when she stashes her stolen clothes with Brenda, the police get involved, forcing Brenda to clear her name.
Brandon finds mixed blessings when Sheryl, his former girlfriend from Minnesota, comes for a visit, and who falls victim to the fast nightlife of the city. Meanwhile, Brenda develops a crush on her math teacher which affects her even more when she's asked to baby-sit for his two wild children for the evening in which Brenda asks Kelly and Donna to tag along with her.
Brenda botches her third try to get her drivers license, but she goes out anyway to rescue Kelly from a bad date, and in the process, loses Brandon's car. Meanwhile, Brandon decides to try out for the school's basketball team where he suspects that some students are brought into the school from out of district for the sole purpose of winning games and he asks Andrea to look into it.
Close to failing history, Brandon (at Steve's persuasion) resorts to cheating from a copied term paper, which leads him to debate honesty vs. an unfair teacher, as well as his friendship with Andrea when she catches him cheating. Meanwhile, Brenda and Kelly both have the hots for Dylan, so Brenda tries dying her hair after he states his preference for blonds. But she comes out with ugly orange streaks.
Brenda becomes fascinated by Kelly's hip mother Jackie. But Brenda is unaware about Mrs. Taylor's alcoholism and drug use which makes life hard for Kelly. It's not until at a West Beverly High Mother/Daughter beauty pageant that Brenda finds the truth which gives her a renewed appreciation for her own mother. Andrea blossoms at the pageant while writing an article about it. Also, Jim becomes hooked on playing his new electronic keyboard in singing old songs.
While Jim and Cindy celebrate their 17th wedding anniversary, Cindy finds herself attracted to photographer Glen, her old college boyfriend and matchmaker, which resurrects old jealousies from Jim. Meanwhile, Brenda and Brandon participate in a study on twins in America. Also, David is determined to become the new DJ on West Beverly High's radio station and after the dim-witted Scott blows his spot, Donna overplays her part, and Steve gets stage fright.
Brenda finds herself in a crisis when she gets to know an unseen student date-rape victim from Andrea's volunteer help line. Meanwhile, Brandon gets tempted by an older woman, named Nina, who specializes in health massage solutions.