While in the midst of practicing a Bronx accent and preparing for his role, De Niro met both LaMotta and his ex-wife, Vikki on separate occasions. Vikki, who lived in Florida, would tell stories about her life with her former husband and also show old home movies (that would later inspire a similar sequence to be done for the film). Jake LaMotta, on the other hand, would serve as his trainer accompanied by Al Silvani as coach at the Gramercy club in New York getting him into shape. The actor found that boxing came naturally to him; he entered as a middleweight boxer, winning two of his three fights in a Brooklyn ring dubbed "young LaMotta" by the commentator. According to Jake LaMotta, he felt that De Niro was one of his top 20 best middleweight boxers of all time.

The film began shooting at a Los Angeles warehouse in April 1979. The warehouse was modified to replicate the Madison Square Garden venue in New York as the site of the boxing scenes. Scorsese made it clear during filming that he did not appreciate the traditional way in films to show fights from the spectators' view. He insisted that one camera operated by the Director of Photography, Michael Chapman would be placed inside the ring as he would play the role of an opponent keeping out of the way of other fighters so that we could see the emotions of the fighters, including those of Jake. The precise moves of the boxers would be done as dance routines from the information of a book about dance instructors in the mode of Arthur Murray. A punching bag which sat in the middle of the ring was used by De Niro between takes before aggressively coming straight on to do the next scene. The initial five-week schedule for the shooting of the boxing scenes took longer than expected, putting Scorsese under pressure.

According to Scorsese, production of the film was then closed down for around four months with the entire crew being paid, so De Niro could go on a binge eating trip around Northern Italy and France. When he did come back to the United States, his weight increased from 145 to 215 pounds (66 to 97 kg). The scenes with the heftier Jake LaMotta — which include announcing his retirement from boxing and LaMotta ending up in a Florida cell — were completed while approaching Christmas 1979 within seven to eight weeks so as not to aggravate the health issues which were already affecting De Niro's posture, breathing, and talking. The final sequence where Jake LaMotta is sitting in front of his mirror was filmed on the last day of shooting taking 19 takes, with only the thirteenth one being used for the film. Scorsese wanted to have an atmosphere that would be so cold that the words would have an impact as he tries to come to terms with his relationship with his brother.

The editing of Raging Bull began when production was temporarily put on hold and was completed in 1980. Scorsese worked with the editor, Thelma Schoonmaker to achieve a final cut of the film. Their main decision was to ditch Schrader's idea of LaMotta's nightclub act intervening with the flashback of his youth and instead just follow along the lines of a single flashback where only scenes of LaMotta practicing his stand-up would be left "bookending" the film. A sound mix arranged by Frank Warner was a delicate process taking six months. According to Scorsese, the sound on Raging Bull was difficult because each punch, camera shot, and flash bulb would be different. Also, there was the issue of trying to balance the quality between scenes featuring dialogue and those involving boxing (which were done in Dolby). Raging Bull went through a test screening in front of a small audience including the chief executives of United Artists, Steven Bach and Andy Albeck. The screening was shown at the MGM screening room in New York around July 1980. Later, Albeck praised Scorsese by calling him a "true artist". According to the producer, Irwin Winkler, matters were made worse when United Artists decided not to distribute the film but no other studios were interested when they attempted to sell the rights. Scorsese made no secret that Raging Bull would be his "Hollywood swan song" and he took unusual care of its rights during post-production. This caused some friction with Irwin Winkler, who accused Scorsese of doing the editing process "inch by inch". Scorsese threatened to remove his credit from the film if he was not allowed to sort a reel which obscured the name of a whisky brand known as "Cutty Sark" which was heard in a scene. The work was completed only four days shy of the premiere.

The unsettling brew of violence and anger, combined with the lack of a proper advertising campaign, led to the film having a modest box office intake of $23 million. Scorsese became concerned for his future career and worried that producers and studios might refuse to finance his films. According to Box Office Mojo, the film grossed $23,383,987 in domestic theaters.

Raging Bull first premiered in New York on December 19, 1980 to mixed reviews. Jack Kroll of Newsweek called Raging Bull "the best movie of the year" Vincent Canby of The New York Times said that Scorsese "has made his most ambitious film as well as his finest" and went on to praise Moriarty's debut performance as "either she is one of the film finds of the decade or Mr. Scorsese is svengali. Perhaps both." Time praised De Niro's performance since "much of Raging Bull exists because of the possibilities it offers De Niro to display his own explosive art". Steven Jenkins from the British Film Institute's (BFI) magazine, Monthly Film Journal said "Raging Bull may prove to be Scorsese's finest achievement to date". Many critics however were repelled by the film's violence and its unsympathetic central character. For example, Kathleen Carroll from The New York Times criticized the character of Jake LaMotta as "one of the most repugnant characters in the history of the movies"; she also faulted Scorsese because the movie "totally ignores [LaMotta's] reform school background, offering no explanation to his anti-social behavior".

Raging Bull was nominated for eight Academy Awards (including Best Picture, Director, Actor, Supporting Actress, Supporting Actor, Cinematography, Sound, and Editing) at the 1980 Academy Awards. The Oscars were held the day after President Ronald Reagan was shot by John Hinckley Jr., who was obsessed with Scorsese's Taxi Driver. Out of fear of being attacked, Scorsese went to the ceremony with FBI bodyguards disguised as guests who escorted him out before the announcement of the Academy Award for Best Picture was made - the winner being Ordinary People. Nevertheless, the film managed to pick up two awards including Best Actor (De Niro) and Best Editing (Schoonmaker).

The Los Angeles Film Association voted Raging Bull the best film of 1980 and best actor for De Niro. The National Board of Review also voted best actor for De Niro and best supporting actor to Pesci. The Golden Globes awarded another best actor award for De Niro and National Society of Film Critics gave best cinematography to Chapman. The Berlin Film Festival chose Raging Bull to open the festival in 1981.

By the end of the 1980s, Raging Bull had cemented its reputation as a modern classic. It was voted the best film of the 1980s in numerous critics' polls and is regularly pointed to as both Scorsese's best film and one of the finest American movies ever made. Several prominent critics, among them Roger Ebert, declared the film to be an instant classic and the consummation of Scorsese's earlier promise. Ebert proclaimed it the best film of the 1980s, and the fourth greatest film of all time. The film has been deemed "culturally, historically, or aesthetically significant" by the United States Library of Congress and was selected for preservation in the National Film Registry in 1990.