Erros de gravação

Early on in the movie, Jake tells Joey to punch him. Joey does so, repeatedly, and leaves his ring on thereby cutting Jake with each new punch. Yet right before he throws the last punch, all of the puncture wounds in Jake's forehead have been removed.

As Joey is punching his brother Jake in Jake's kitchen, blood appears on Jake's face. When Joey stops the punching, the blood disappears.

When Jake is sitting by the TV arguing with Joey, the bunny ears on the TV change positions between shots.

When Jake and Joey are trying to set the TV antenna towards the end of the film, the screen noise pattern is different in close-ups and wide shots.

When Jake is in the bathroom pouring ice water down his pants, the bruise on his eye has disappeared.

Joey and Jake attend a dance that occurs on "Saturday," 6 August 1941. This date was a Wednesday.

Jake first spots Vickie somewhere between 1941 and 1943 and Joey points out to Jake that she is 15 years old. However, Vickie La Motta was born in 1930 meaning that she would not have been 15 years old until 1945.

In the beginning, in what is supposed to be the first loss of LaMota's career, after the fight against Jimmy Reeves, the ring announcer says the result is by Unanimous Decision. The first loss of LaMota's career and first loss to Jimmy Reeves, is by Split Decision. The second loss is the one by Unanimous Decision.

In the final fight between Jake and Sugar Ray Robinson. Just before Robinson hits Jake in the face and blood gushes out of his nose, he is pushed up against the ropes. However, although it's very quick, he is pushed up against the ropes with a bare white hand, not one with a boxing glove.

When Joey supposedly kisses Vicki on the lips Jake is clearly looking away at the TV trying to fix it.

When Jake follows Joey into the parking garage, hip-hop-style graffiti is visible outside it.

In Jake's nightclub in 1956, background music is Frank Sinatra's 1957 recording of Come Fly With Me.

When Jake is in the phone booth towards the end of the movie saying that he wouldn't be able to raise the $10,000 that he needed, his lips aren't moving.

When Jake and Joey are sitting at the kitchen table, Jake tells Joey to grab a towel to hit him. When Joey picks it up Jake says "Now wrap it around your hand," but the first half of the sentence seen from behind Jake focusing on Joey, Jake's mouth is not moving.

In the entrance to the last fight as Jake makes his way to the ring you can hear the ring announcer but as Jake passes the bottom of the ring the announcer has his hand by his side holding the microphone, therefore not able to be broadcasting.

In La Motta's final fight with Sugar Ray: La Motta can be seen going over and taunting Ray by saying "I never went down man, you never got me down Ray, do you hear me? You never got me down". As he is being dragged away by one of his own team you can hear La Motta say "See look," but his lips don't move.

A rubber tube, to carry fake blood, is visible behind Janiro's nose as Jake punches it.

As Jake hurries to the bathroom after pouring ice water down his shorts, the top of a crewmember's head appears briefly in the lower left-hand side of the screen. (This may be peculiar to the 1988 MGM/UA videotape version.)

In a shot that introduces Jake's post-boxing life in Florida, the license tags of his two Cadillacs are shown in close-up. One of the Florida plates bears a "5" prefix, which in the 1950s indicated an automobile registered in Polk County (Lakeland). If Jake was living in the Miami area, it's far more likely his automobiles were registered in Dade County (prefix "1") or perhaps Broward ("10"), but not in a county 150 miles away.

Jake is shown knocking out Tony Janiro. Jake is then announced the winner by "unanimous decision."

When Billy Fox is weighed in before his fight with La Motta his weight is confirmed as 173 and 3/4 pounds, but when the MC introduces Fox before the fight he states Fox's weight as 175 pounds.