Muhammad Ali, then known as Cassius Marcellus Clay, Jr., appears as Quinn's opponent in a boxing match at the beginning of the movie.

Maish responds forcefully and eloquently to Grace's accusation that he has been over-controlling of Mountain, disputing the notion that he cares nothing for the boxer, his best interests, and his future.

He tells Grace that she must stop daydreaming and recognize that her idealized conception of Luis Rivera is as false and damaging to the fighter as is Maish's alleged mediocre management of the boxer's career.

Further, he tells her that her so-called "vision" for Rivera's post-boxing future as a counselor at a children's summer camp is as naïve and pathetic as it is improbable.

In the final scene of the film, Mountain enters the ring amidst jeering ridicule to face Haystack Calhoun, a wrestler from Arkansas billed at 601 pounds (273 kg).

Rotten Tomatoes gives it a rating of 89% from a sample of 46 critics with the consensus: "Requiem for a Heavyweight is a stirring character study of a battered boxer that may at times pummel its message yet retains cinematic métier and human nobility.