Memories...

Erik Stifler (John White) has a difficult time living up to his family name. He is perhaps the only Stifler about to graduate from high school as a virgin. The film opens with Erik feigning illness so that he can stay home and masturbate to an old VHS pornographic film he found in a dumpster. Unfortunately, just as he is about to ejaculate, his parents and grandmother unexpectedly walk into the door and are hit with Erik's semen. His grandmother dies from a heart attack brought on by the shock. Erik's dad later surmises that as a Stifler, his son should be out having sex instead of masturbating. Erik's attractive girlfriend of two years, Tracy (Jessy Schram), loves him for all of his awkwardness, but unfortunately she is not ready for intercourse. Alas, their first attempt at sex goes horribly wrong. Erik has a dodgy stomach and suffers badly from flatulence, resulting in Tracy's father hearing him pass wind and mistake him for a naked intruder. Erik ends up defecating in their tumble dryer.

Erik's friends Cooze (Jake Segal) and Ryan (Ross Thomas) plan a road trip to visit Erik's cousin Dwight, a.k.a. Stifler (Steve Talley) in Michigan during an infamous university event known as the Naked Mile. Tracy sees this as an opportunity to give Erik a "guilt free weekend pass," hoping that he can quench his lust and get it all out of his system since she is not ready for sex.

Erik and his friends arrive on campus to find that his cousin Dwight truly lives up to his legendary wild reputation. They witness an over-the-top drinking contest where Dwight is crowned a campus champion, lose a rough game of football against a bitter rival fraternity composed almost entirely of midgets, and end up in a brawl with those same midgets on several occasions. This rivalry comes to a head when the midget fraternity attacks Dwight, landing him in the hospital, where he reveals that he appreciates Erik for being a stand-out decent guy in the Stifler family. This provides some perspective for Erik, who has been desperately seeking to live up to the name. Luckily, Dwight is back in full form later that evening when it is time for the naked mile run, partying with many beautiful women.

Erik meets a college girl with a fetish for virgin boys, and as they steal a kiss a news crew is able to capture the moment. Cooze and Ryan each meet girls with their own unique fetishes. Watching the news report about the Naked Mile back at home, Tracy is upset and guilty that she allowed Erik the free pass in Michigan. Her friends convince her to also lose her virginity before he gets back so that she will be on equal footing with her boyfriend, lest he be more experienced than her. Later that evening, as Erik receives oral sex from the college girl, he realizes that he loves Tracy and rushes back to see his girlfriend. When his car runs out of gas, he steals a horse and goes to Tracy's house to see if she is there. Tracy's dad says she is at a party, then Erik arrives at the party just as Tracy has headed upstairs, presumably to lose her virginity to her ex-boyfriend. Erik loudly pounds on the closed bedroom door, proclaiming his love for her. Tracy was not in that room, but she heard everything he said and is moved by his heroic efforts and they embrace to great applause by the crowd that has gathered. It turns out that she couldn't go through with her plans either, so she's not in the bedroom.

Later that evening, Tracy and Erik decide that they should be each others' first. They make tender love and fall asleep in each others' arms. When Erik returns to the college to pick up his friends the next morning, each boy shares stories of his experiences from the night before. Ryan declares that Erik has finally earned the right to be called "Stifler." Although Erik is appreciative, he realizes that he just wants to be known as himself and not by his family's reputation. In the end of the movie, the 3 friends drive off back to Michigan. Rock (the midget leader) brings in the mail for his fraternity and he receives a DVD for himself, reading "Payback's a Bitch" on the CD. He plays the DVD revealing Dwight Stifler and Rock's girlfriend having sex. Dwight sticks up his middle finger to the camera and then says, "Smile for the camera baby." Rock's girlfriend looks at the camera, gives a grin, and goes back to kissing Dwight. Finally, Rock shouts out "STIFLER!" and the movie ends.