Zack finally pursues Laney, who forgives him for the bet. The two kiss while dancing at her house and Zack says he wants to go to the same art school that Laney will attend.
Zack Siler's (Freddie Prinze Jr.'s) high school career is going well. He is a player on the soccer team, elected as school president, is uber-popular and has one of the top GPAs in the school. He also is dating the hottest girl in school,Taylor Vaughan (Jodi Lyn O'Keefe). There are only six weeks of school left and Zack and Taylor are the presumptive favorites for Prom king and queen. Unfortunately, Taylor breaks up with Zack after falling for Brock Hudson (Matthew Lillard), a narcissistic cast member of the TV Show The Real World.
While being consoled by his friends Dean Sampson (Paul Walker) and Preston (Dulé Hill), they make a bet. Zack claims he can take any girl and have her elected Prom Queen in the next six weeks. Dean chooses an angry, artistic, socially awkward and klutzy girl named Laney Boggs (Rachel Leigh Cook) as the subject of the bet. Laney initially blows Zack off, believing him to be shallow. Although Zack's sister Mackenzie (Anna Paquin) is impressed by Laney's total dismissal of Zack, she ultimately helps Zack try to win his bet by telling him that he needs to take a genuine interest in her life.
Zack attends an art-show that Laney is in and even agrees to do some performance art himself. He also befriends Laney's dorky younger brother Simon (Kieran Culkin) and her father Wayne (Kevin Pollack). He also discovers that Laney's mother died when Laney and Simon were very young after succumbing to cancer. Meanwhile, Laney becomes more open, hanging out with Zack's friends. His friends begin accepting Laney, including popular girl Katie (Gabrielle Union). Lanie also learns that despite his looks and his brains, Zack is terrified of the future, refusing to choose a college despite having been accepted by all the Ivy League universities.
The two become friends and ultimately, are attracted to each other. Their initial romance blossoms when Mackenzie gives Laney a stylish makeover and she agrees to attend a party at Preston's house. While at the party, Laney is publicly humiliated by Taylor. Their fight results in a heated campaign between the two women for Prom Queen, with Laney supported by Katie as well as the school geeks. Meanwhile, Brock breaks up with Taylor (using the same break-up line on her that she used on Zack). Taylor immediately demands that Zack date her again and accompany her to homecoming. Zack feels peer pressure to do so. Meanwhile, Dean decides he wants to have sex with Laney and asks her to Prom, telling her about the bet in the process. Laney is devastated by Zack's betrayal and decides she won't go to Prom at all.
On Prom night, however, Dean shows up at Laney's house to try and take her anyways. After some prodding by her dad, she ultimately relents and agrees to go with him. Meanwhile, Zack has decided to take Mackenzie to Prom so that he can find and win Laney back. Mackenzie ends up meeting and taking a romantic interest in Laney's best friend, Jesse (Elden Henson). Unfortunately, Taylor intercepts Zack and prevents his attempts to get to Laney. While at Prom, Laney's art teacher said her recent work is the best she has ever produced and that she should make sure to keep whatever has changed her life (and therefore, her art). She stares wistfully at Zack as he dances with Taylor.
The results are announced for Prom Queen and King. Zack is handily electing Prom King, and in the closest-ever election in school history, Taylor wins Prom Queen. Laney is disappointed despite acknowledging that the election meant more to Taylor. She and Dean leave during the acceptance speeches. Mackenzie and Jessie discover Dean's plans to sleep with Laney and finally are able to tell Zack, but they have no idea where Dean and Laney have gone. Zack leaves Prom while Taylor gives a self-serving Prom Queen speech.
We jump ahead to Laney coming home alone. Wayne tells her that she has someone waiting for her and finds Zack waiting in her backyard. Laney explains that when she figured out what Dean was up to, she used a blowhorn to deafen him and then took a cab home. Zack asks her for the "last dance," but Laney says it will actually be their "first dance." Zack admits that he is planning to attend art school with Laney. The two then finally kiss.
The film ends at graduation. We see that Dean is still somewhat deaf and that Zack, having lost the bet, is required to walk the stage naked.
This film also includes small roles and cameos for the singers Usher and Lil Kim, as well as Clea DuVall, Tim Matheson, Chris Owen, Milo Ventimiglia and Sarah Michelle Gellar.