Trivia: During the scene before the fight, where Rocky enters the ring and sees the 2 portraits of him and Apollo, the error on Rocky's shorts was an actual error made by the art crew, and Sylvester Stallone rewrote the scene when he saw this mistake.
Trivia: After this movie was released, the character Engleberg had to be recast because the actor who played him lost a lot of weight and no longer could play the "fat" catcher so a new heavy actor replaced him in the next two sequels.