Professional boxers played Braddock's opponents. They were told to land their blows as close to Crowe's body as possible. Unfortunately, they sometimes couldn't pull back in time and ended up injuring Crowe.
Crowe suffered from several concussions and cracked teeth.
The cinematographer invented a "tire-cam" which is a camera cushioned inside a tire and behind Plexiglas. This allowed the professional boxers to hit the tire to create realistic reactions from a first-person point-of-view.
At one time, Penny Marshall was intended to direct the film.
Rosemarie DeWitt, who plays the neighbor Sara Wilson, is the granddaughter of the real Jimmy Braddock. She is the daughter of his daughter Rosemarie, who is portrayed by Ariel Waller in the film.
This Depression-era drama made headlines for being not only one of the best reviewed films of 2005, but one of the least well attended. After four weeks of release the film had taken around US$50 million, which even during the box-office slump of the time was a disappointment, especially considering the good buzz. AMC Theatres hoped to keep the film and started a unique offer of a money-back guarantee. Ticket buyers who did not like the film were promised that their money would be refunded, no questions asked.
The streetcars used in the movie are owned by the Halton County Radial Railway Museum, which has a huge collection of streetcars near Milton, Ontario, Canada.
Max Baer, who's paternal grandfather was Jewish, boxed with a Star of David embroidered on his trunks. The star is visible on Baer's red trunks throughout his fight with Braddock in the final fight scene.
Madison Square Garden Bowl was located at 48th Street and Northern Boulevard in Long Island City, Queens. The bowl was torn down after World War II.
The story Braddock tells of his kids confusing the word "title" with the word "turtle" is true. A reporter asked Braddock's son Howard what he would do if his father brought home the title young Howard replied that he'd "play with it. Pull it around on a string".
One of the boxers portrayed in the film was Frankie Campbell. Campbell's real name was Frankie Camilli. His brother was Brooklyn Dodger all star first baseman Dolph Camilli.
After the film's release many boxing analysts and even Max Baer's son, Max Baer Jr. decried the movie for it's historical liberties taken with Max Baer. Specifically, that he had killed two men in the ring (he did kill one and an opponent he'd KO'd died a few weeks after their bout for reasons unrelated to the fight) and that he took pride in that fact. Max Baer Jr. has said that his father was always haunted by the memories of killing a man in the ring and that it played a prominent part in Max Baer's eventual death from alcoholism.
Russell Crowe dislocated his shoulder while training for the film's boxing sequences, which delayed the filming two months.
According to Steve Kroft during an interview with Russell Crowe on an episode of "60 Minutes" (1968), the role of Jim Braddock is Crowe's personal favorite.
The movie, which cost around $90 million to make, did less well than expected, taking around $60 million at the US box office.