Songs by Bob Seger were substituted in place of those by Bruce Springsteen shortly before the film's release after a failure to reach agreement with Springsteen.
According to Peter Bogdanovich, on Sunday, 14 March 2004, in a talk at the Cleveland Public Library (Ohio), he has secured the rights for the Bruce Springsteen songs and the print will be re-released with the music chosen the first time around. There was a possible snag when the studio told Bogdanovich that the negative of the film had been lost - they only had positive prints - but the negative hadn't really been lost - Bogdanovich had removed it from the studio some years prior.
Eric Stoltz spent so much time under heavy makeup that when he arrived for the post production party he had to present I.D. to security to prove that he was Eric Stoltz. Also, when he got there he had to introduce himself to some of the cast and crew because many of them didn't know what he really looked like.
Bruce Springsteen's music was chosen for several reasons. It was the real Rocky's favorite music, and it served to denote the passage of time. Springsteen wanted his music used in the original release, but the owners of his catalog at that time could not agree on a royalty rate with the studio. The music was reinstated for the Director's Cut when Springsteen himself pushed for its inclusion.
Florence "Rusty" Tullis, the mother of Rocky Dennis, passed away on November 11, 2006, at age 70 from injuries sustained in a motorcycle accident on October 14. Ms. Tullis was portrayed by Cher in Mask.
Rusty actually had two sons. The older son, Joshua Mason, passed away in 1987 at age 32 due to complications from AIDS, which he received through a blood transfusion.
The trivia items below may give away important plot points.
The movie ends with Rusty Dennis and Gar visiting Rocky's grave. In real life, however, Rocky Dennis was not buried. His mother donated Rocky's body to the UCLA Medical Center for medical study.