M*A*S*H, unlike many war films had an anti-war message, but delivers it with a light touch—shown through moderate anarchy, bizarre conversation, and the boredom, stress, and resentment of the drafted physicians. The film's critics disliked the film's limits on war carnage in favor of camp existence, and also for a certain callous attitude, notably in the treatment of the characters played by Robert Duvall and Sally Kellerman.
The film is episodic, with considerable changes in tone and marked by Altman's trademark style of overlapping conversations or sounds and unusual use of zoom. In the director's commentary on the DVD release of this film, Altman claims that this was the first movie to dare use the word "fuck" (spoken during the football game near the end of the film). This is perhaps untrue, however, as the movies I'll Never Forget What's His Name and Ulysses (both released in 1967) each claim to be the first to utter the famous profanity.
The film has been deemed "culturally significant" by the Library of Congress and selected for preservation in the United States National Film Registry.
The film won the 1970 Palme d'Or (Golden Palm) at the Cannes Film Festival.
The M*A*S*H features the song "Suicide is Painless", with music by Johnny Mandel and lyrics by Mike Altman, the director's son. The television show used an instrumental version as its theme tune.