The 14-year-old son of Robert Altman, Mike Altman, wrote the lyrics to the theme song "Suicide is Painless". Because of its inclusion in the subsequent TV series, he continued to get residuals throughout its run and syndication. His father was paid $75,000 for directing but his son eventually made about $2,000,000 in song royalties.
The first take of the shot where Hot Lips is revealed in the shower didn't work because Sally Kellerman anticipated the reveal and was already lying on the floor when the tent flap went up. To distract her, Robert Altman and Gary Burghoff entered the shower tent and dropped their trousers while the shot was rolling outside. While Kellerman was staring at them, the tent flap was raised, resulting in her genuine surprise and shock when she realized what had happened. In the special double disc dvd they say that Radar is standing naked beside the camera and that that's the reason why Sally Kellerman looks so surprised when the flap was raised.
Robert Altman said that during filming, Elliott Gould and Donald Sutherland together went to the studio and complained that Altman was filming too much of the secondary characters. They requested that he be removed from the film, but the studio refused. After the film was completed and received its accolades, only Gould confessed the matter to Altman. As a result, he received parts in other Altman pictures, whereas the director never again used Sutherland.
In the opening titles, when a soldier carrying a wounded soldier on a stretcher and when the soldier trips and falls down, it wasn't scripted. It was actually an accident by the actor who tripped over something. Robert Altman decided that instead of editing it out, to use it to foreshadow the dark humor theme as the movie's first small, but real, laugh.
The operating scenes were almost cut out due to their graphic nature. However, two women who were visiting the set told the producers that the operating scenes were what made the movie, and should be kept in.
The story goes that Robert Altman was editing the movie with his editor, Danford B. Greene; they had nude pinups on the walls of the editing room. The head of postproduction came by and tried to stop Altman from using the editing machine, as he wasn't a designated editor, and Altman threw him out of the editing room. The next day a memo came down from the Fox front office, stating a new policy that there were to be no pinups on the walls of editing rooms. Altman took the memo to the sound recording studio and added it as one of the loudspeaker announcements during the film.
Tom Skerritt recalled that the dialogue was about 80% improvised. In order to create a different kind of atmosphere, Robert Altman cast some of the parts from improvizational clubs who had no previous movie experience.
The scene where Father Mulcahy is blessing the jeep was improvised. Actor Rene Auberjonois found the blessing in a copy of the Army Chaplain's Handbook, and thought it would be a good addition to both the story and to his character. The director agreed, and the scene was shot in one take.
Robert Altman felt that he was able to get away with so much during shooting because the officials at 20th Century Fox were keeping a closer watch on their two massively expensive projects, also war films, Patton (1970) and Tora! Tora! Tora! (1970).
During filming Donald Sutherland and Elliott Gould became so frustrated with the directorial style of Robert Altman (who often had his actors talk over each other at the same time, to simulate real life conversation), that they went to the head of production to demand he be fired. They were concerned that the movie would end up as a mess, and a movie disaster at the box office might ruin their careers. They were told by the studio head not to worry, that the movie would only be seen at a few drive-ins across the country, and that hardly anyone would ever see the movie.
One innovation of Robert Altman was the almost constant overlaying of dialogue: as many as four conversations could be happening at once in a given shot. While this was considered unorthodox and revolutionary at the time, Altman's instinct was vindicated when audiences agreed that the technique contributed to the feeling that war was "messy and confusing". The technique has been emulated on several occasions since.
The opening title sequence has a text that identifies the place as Korea. This was added at the insistence of the studio after director Robert Altman had removed every reference to Korea, intending it to be mistaken for Vietnam, which would reinforce the anti-war statement.
When studio execs first saw the dailies, they complained to Robert Altman that the soldiers looked dirty compared to the soldiers in Tora! Tora! Tora! (1970) and Patton (1970). Altman, a veteran of WWII, replied that soldiers in war are dirty. The next day the execs told the producers of those two films to make their soldiers look dirtier.
According Johnny Mandel and Robert Altman, the film's famous theme song was intended to be the "stupidest song ever written". After attempting to write the lyrics himself, Altman said he found it too difficult to write "dumb enough", and instead gave to the task to his 14 year old son. Mike Altman apparently wrote the lyrics in five minutes.
According to Robert Altman was the first R rated movie to use the word "fuck" in it, but apparently it wasn't his idea. During second-unit shooting for the football game that comes near the end of the film, John Schuck was told to say something "really nasty" to his opponent. Schuck came up with "All right, bub, your fucking head is coming right off," and it made it into the film's final cut.
According to Elliott Gould, Sylvester Stallone revealed to him that he was an extra in this film. When Gould later told this to Robert Altman, Altman refused to accept this as fact because he was not a fan of Stallone's work.
The loudspeaker shots and announcements were added after the editing process had begun and the filmmakers realized that they needed more transitions. Some of the loudspeaker shots have the Moon visible and were shot while the Apollo 11 astronauts were on the Moon.
Robert Altman was initially considering James Garner for the part of Hawkeye until Donald Sutherland lobbied hard for the role. James Garner was an actual Korean War veteran who had been wounded and treated in military hospital during the conflict.
When the movie was released, the military wanted not to run the movie in their theaters because of its anti-war message. The case went to the Supreme Court which ruled the military could not withdraw the film for this reason. Instead, the military chose to run Patton (1970) in the following week feeling that film was more complimentary to the military.
Robert Altman was originally promised five "points" (a percentage) of the film's profits. After a disagreement between Altman and one of the Fox executives, the offer of points was taken back before production began. When the film became a big hit, Altman's agent asked for the points back; the studio was considering it when Altman was quoted in the press saying how much he hated working for Fox. He was never given the points back.
Writer Ring Lardner Jr. was the only Academy Award winner out of the movie's five nominations. Lardner practically disowned the movie when he saw that very little of his original script made it into the final cut.
This was not the first Korean War-based movie to carry the title "MASH." In 1953, Humphrey Bogart starred in a film also about a MASH unit by the same title. But the studio thought the title might make audiences think it was about potatoes, so the title was changed to Battle Circus (1953).
This and Catch-22 (1970), two films satirizing recent American wars, were released in the same year. "Catch-22," based on a best-selling novel, featuring a huge cast, and boasting director Mike Nichols fresh from his success with The Graduate (1967), was expected to be the more successful film. When the reverse proved true, Robert Altman hung a banner in his office reading, "Caught-22."
This film was among the first to be released on home video. In 1977 20th Century Fox licensed 50 of its titles to a fledgling video duplication company called Magnetic Video Corp. Fox purchased the company in 1978, laying the groundwork for its current successful video operation.
Robert Altman originally wanted Elliott Gould to play Duke Forrest. It was only at Gould's request that he got the role of Trapper John, as he was worried that he would spend more time focusing on the accent.
In the scene when Major Houlihan storms into Colonel Blake's tent after being exposed in the shower, Sally Kellerman shouted her scripted lines at Roger Bowen, and then noticed that Robert Altman was keeping the camera running. Kellerman, not knowing what else to do, continued sobbing her final words of dialogue, "My commission...my commission..." until finally Altman ordered the camera to cut. Following the scene, Altman embraced Kellerman and told her she had finally revealed the vulnerability in the character he'd been hoping for. Unfortunately, the scene was the final appearance in the script of the Houlihan character. But because of Altman's delight with Kellerman's improvised performance in the scene, the director kept her on the film for the duration of filming, and inserted the actress into additional scenes in which she was not scripted, such her cheer-leading as the football game, observing the poker game, and even the scene late in the picture which revealed her character had become romantically involved with Captain Duke Forrest.
According to George Litto, when studio executives first saw the film, they handed Altman "10 pages of notes for cuts and changes they wanted made," then producer Ingo Preminger arranged a test screening in San Francisco. By the time Hawkeye was stealing the Jeep, the audience was openly applauding the film, and executive Richard D. Zanuck apparently said, "Tell Bob to forget about my notes."
For "Hot Lips" shower scene, Robert Altman had to deploy a few distractions. Sally Kellerman had never appeared nude onscreen before, and in early takes of the scene she was dropping to the ground before the point of the moment was even made clear. So Robert Altman had to think of distractions to get her to pause before falling to the ground. These included Gary Burghoff standing naked in front of her and Tamara Wilcox-Smith standing out topless. Kellerman attributes her Oscar nomination to them.
The film is radically different from the novel. Robert Altman described the novel as "pretty terrible" and somewhat "racist" (the only major black character has the nickname "Spearchucker"). He claims that the screenplay was used only as a springboard. However, the screenplay itself reveals that, while there is some improvisation in the film, and although Altman moved major sequences around, most sequences are in the screenplay. The main deletion is a subplot of Ho-Jon's return to the 4077th-as a casualty. When Radar steals blood from Henry, it is for Ho-Jon's operation under Trapper and Hawkeye's scalpels. When the surgeons are playing poker after the football game, they are resolutely ignoring a dead body being driven away-Ho-Jon's. The main deviation from the script is the trimming of much of the dialogue.
According to Robert Altman, Ring Lardner Jr. was very upset with the liberties taken with his script. Lardner later won an Academy Award for his screenplay. Lardner apparently told Elliott Gould, "There's not a word that I wrote on screen."
During production, a caption that mentions the Korean setting was added to the beginning of the film, at the request of 20th Century Fox. The Korean War is explicitly referenced in announcements on the camp public address system and during a radio announcement that plays while Hawkeye and Trapper are putting in Col. Merrill's office which also cites the film as taking place in 1951.