Raging Bull came about when De Niro read the autobiography upon which the film is based on the set of The Godfather Part II. Although disappointed by the book's writing style, he became fascinated by the character of Jake LaMotta. He showed the book to Martin Scorsese on the set of Alice Doesn't Live Here Anymore in the hope that he would consider the project. Scorsese repeatedly turned down the opportunity to sit in the director's chair, claiming he had no idea what Raging Bull was about, even though he had read some of the text. Never a sports fan, when he found out what LaMotta used to do for a living, he said, "A boxer? I don't like boxing...Even as a kid, I always thought that boxing was boring... It was something I couldn't, wouldn't grasp." His overall opinion of sport in general is, "Anything with a ball, no good." The book was then passed onto Mardik Martin, the film's eventual co-screenwriter, who said "the trouble is the damn thing has been done a hundred times before—a fighter who has trouble with his brother and his wife and the mob is after him". The book was even shown to producers Robert Chartoff and Irwin Winkler by De Niro, who were willing to assist only if Scorsese agreed. After nearly dying from a drug overdose, Scorsese agreed to make the film for De Niro's sake, not only to save his own life but also to save what remained of his career. Scorsese knew that he could relate to the story of Jake LaMotta as a way to redeem himself; he saw the role being portrayed as an everyman for whom "the ring becomes an allegory of life", making the project a very personal one for him.
Preparation for the film began with Scorsese shooting some 8mm color footage featuring De Niro boxing in a ring. One night when the footage was being shown to De Niro, Michael Chapman, and his friend and mentor, the British director Michael Powell, Powell pointed out that the color of the gloves at the time would have only been maroon, oxblood, or even black. Scorsese decided to use this as one of the reasons to film Raging Bull in black and white. Other reasons would be to distinguish the film from other color films around the time and to acknowledge the problem of fading color film stock—an issue Scorsese recognized. Scorsese even went to two matches at Madison Square Garden to aid his research, picking up on minor but essential details such as the blood sponge and later, the blood on the ropes (which would later be used in the film). According to the brief comments on the inlay card of the Raging Bull DVD, Scorsese was - and still is not a fan of sport ['Anything with a ball, no good.'] or boxing, which he describes as boring. When he was the blood-soaked sponges being dipped in bucket, he recalls thinking to himself, 'And they call this sport.' When DeNiro first broached the idea to him, Scorsese's initial reactin was, 'A boxer? I don't like boxing.' Cooler heads prevailed, however, and hence, the movie was made.
Under the guidance of Chartoff and Winkler, Mardik Martin was asked to start writing the screenplay. According to De Niro, under no circumstances would United Artists accept Mardik Martin's script. The story was based on the vision of journalist Peter Hamill of a 1930s and 1940s style, when boxing was known as "the great dark prince of sports". De Niro was unimpressed when he finished reading the first draft, however. Taxi Driver screenwriter Paul Schrader was swiftly brought in to re-write the script around August 1978. Some of the changes that Schrader made to the script saw a re-write of the scene with the uncooked steak and inclusion of LaMotta seen masturbating in a Florida cell. The character of LaMotta's brother, Joey, was finally added, previously absent from Martin's script. United Artists saw a massive improvement on the quality of the script. However, its chief executives, Steven Bach and David Field, met up with Scorsese, De Niro, and producer Irwin Winkler in November 1978 to say they were worried that the content would be X-rated material and have no chance of finding an audience.
According to Scorsese, the script was left to him and De Niro, and they spent two and a half weeks on the island of Saint Martin, extensively re-building the content of the film. The most significant change would be the entire scene when LaMotta fixes his television and then accuses his wife of having an affair. Other changes included the removal of Jake and Joey's father; the reduction of organized crime's role in the story and a major re-write of LaMotta's fight with Tony Janiro. They were even responsible for the end sequence where LaMotta is all alone in his dressing room quoting the "I could have been a contender" scene from On the Waterfront. An extract of Richard III had been pondered but Michael Powell thought it would be a bad decision within the context of a film that was American. According to Steven Bach, the first two screenwriters (Mardik Martin and Paul Schrader) would receive credit but since there was no payment to the writer's guild on the script, De Niro and Scorsese's work would remain uncredited.
One of Scorsese's trademarks was casting many actors and actresses new to the profession, and this film was no exception. De Niro, who was already committed to play Jake LaMotta, began to help Scorsese track down unfamiliar names to play his on-screen brother, Joey, and wife, Vickie. The role of Joey LaMotta was the first to be cast. De Niro was watching a low budget television film called The Death Collector when he saw the part of a young career criminal played by Joe Pesci (then an unknown and struggling actor) as an ideal candidate. Prior to receiving a call from De Niro and Scorsese for the proposal to star in the film, Pesci had not worked in film for four years and was running an Italian restaurant in New Jersey. Pesci initially claimed that it would have to be a good role for him to consider it, and he later accepted the part.
The role of Vickie, Jake's second wife, would have interest across the board, but it was Pesci who suggested the actress, Cathy Moriarty, from a picture he once saw at a New Jersey disco. Both De Niro and Scorsese believed that Moriarty could portray the role after meeting with her on several occasions and noticing her husky voice and physical maturity. The duo had to prove to the Screen Actors Guild that she was right for the role when Cis Corman showed 10 comparing pictures of both Moriarty and the real Vickie LaMotta for proof she had a resemblance. Moriarty was then asked to take a screen test which she managed—partly aided with some improvised lines from De Niro—after some confusion wondering why the crew were filming her take. Joe Pesci also persuaded his former show-biz pal and co-star in The Death Collector, Frank Vincent, to try for the role of Salvy Batts. Following a successful audition and screen test, Vincent received the call to say he had received the part. Charles Scorsese, the director's father, made his film debut as Tommy Como's cousin, Charlie.
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.
According to the production mixer, Michael Evje, the film began shooting at the Los Angeles Olympic Auditorium on April 16, 1979. Grips hung huge curtains of black duvetyne on all four sides of the ring area to contain the artificial smoke used extensively for visual effect. On May 7, the production moved to the Culver City Studio, Stage 3, and filmed there until the middle of June. 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 viewers 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.
According to production sound mixer, Michael Evje, Jake's nightclub sequence was filmed in a closed-down San Pedro club on December 3. The jail cell head-banging scene was shot on a constructed set with De Niro asking for minimal crew to be present—there was not even a boom operator.
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 producers Robert Chartoff and 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. 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.
In 2012, Raging Bull was first in a listing of the best edited films of all time compiled by the US Motion Picture Editors Guild.
Paula Petrella, heir to Frank Petrello whose works were allegedly sources for the film, filed for copyright infringement in 2009 based on MGM's 1991 copyright renewal of the film. In 2014, the Supreme Court held that Petrella's suit survived MGM's defense of "laches", the legal doctrine that protects defendants from unreasonable delays by potential plaintiffs. The case was remanded to lower courts, meaning that Petrella could receive a decision on the merits of her claim. MGM settled with Petrella in 2015.