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.
Continuity mistake: In the last scene, at Van Wilder's party, Gwen is talking to Van Wilder and her bathing suit strap is on her left shoulder. When the shot changes, it has disappeared from her shoulder and is on her back. She wouldn't have moved it as her hands don't move in the scene.