Audio problem: When Wendy and Jules are talking in the bathroom, two women walk by and say "Hi Leslie" and "Hi Les, how ya doing?" to Leslie. It is easy to see that their mouths do not move in sync with the words that are heard.
Continuity mistake: In the bar scene when Billy is playing the saxophone on stage, his wife enters the bar with her boyfriend. The saxophone music keeps playing after Billy starts glaring at them, even though Billy has stopped blowing air into the horn and is not pushing the horn's buttons.
Continuity mistake: In the scene where Demi Moore drives Rob Lowe home in her jeep, Demi is wearing white, long earrings. When she tuns to talk to Rob Lowe she has both on them on. When they cut to him and then go back to her she only has one on. Then, again they cut back to Rob Lowe and then back to Demi, she has both of them on again.
Continuity mistake: The characters graduated from Georgetown University, but when Rob Lowe returns to his Fraternity house and plays football, they are actually on the campus of the University of Maryland. This is because Georgetown University wouldn't allow them to film on campus.
Continuity mistake: At end of the movie, Rob Lowe lights two cigarettes when he is in Demi Moore's bedroom. He offers Demi one and she refuses. Rob the takes a cap and puts out of the cigarette, but now the other cigarette he lit is completely disappeared. There is only one cigarette resting in the cap and he does not have the other one in his hand.
Continuity mistake: When the group is first entering St. Elmo's bar after bailing out Rob Lowe, as they enter the bar Judd Nelson is not wearing or carrying a jacket. In the next scene in the bar he is putting on his suit jacket he was wearing earlier at the hospital. (00:10:00 - 00:11:00)
Factual error: When Kirby sees Dale at the ER, he says "You were a senior when I started at Georgetown." That's just three years between them and the gang just graduated from Gtown a few months ago. Dale should still be in med school, years away from becoming a doctor.