Revealing mistake: After Milty jumps off the diving platform, an obvious stunt double, considerably thinner than Milty, completes the dive.
Continuity mistake: During the scene when Van and his friends are riding in Van's golf cart, just after Van has sex with the secretary, the guy in the back is seen being licked on the face by the bulldog. When the camera cuts to Van he's not being licked. When the camera cuts to Van's assistant he's being licked again. This happens over and over. (00:15:53)
Van Wilder: You might want to write that down.
Trivia: The titular character of the movie is based on comedian Bert Kreischer, specifically a Rolling Stone article written about him when he was in his sixth year at FSU and told the story of "the top party guy at the top party school." The writeup eventually become a movie concept that Oliver Stone acquired the rights to, but the deal fell through and the writers sold it to National Lampoon. Kreischer himself was not involved in the movie, however.