The critical reception for MASH was mostly positive. The film currently holds a 90% rating on review aggregator Rotten Tomatoes, based on 39 reviews; the website's consensus stated, "Bold, timely, subversive, and above all funny, M*A*S*H remains a high point in Robert Altman's distinguished filmography."
MASH won the Palme d'Or at the 1970 Cannes Film Festival. It was nominated for five Academy Awards, including Best Picture (lost to Patton), Best Director (lost to Patton), Best Supporting Actress for Sally Kellerman (lost to Helen Hayes for Airport), and Best Film Editing (lost to Patton), and won an Oscar for its screenplay.
The film won the Golden Globe Award for Best Motion Picture (Musical or Comedy) in 1971.
The film was the 38th film to be released to the home video market when 20th Century Fox licensed fifty motion pictures from their library to Magnetic Video.
In 1996, MASH was deemed "culturally significant" by the Library of Congress and was selected for preservation in the United States National Film Registry.
The film is #17 on Bravo's "100 Funniest Movies" and #54 on "AFI" list of the top 100 American movies of all time.
The film was re-released in North America in 1973 and earned an estimated $3.5 million in rentals. In order to attract audiences to the M*A*S*H television series which was struggling with audiences at the time the film was re-released at 112 minutes and received a PG rating. Several scenes were edited including segments of graphic operations, the f-word in the football game, and the scene where the curtain in the shower is pulled up on Hot Lips. "Suicide is Painless", the film's main theme song, was removed from this version and new title music by Ahmad Jamal was used instead according to film critic and historian Leonard Maltin in his movie and video guide. In the 1990s, Fox Video released a VHS version of MASH under their "Selections" banner which ran 116 minutes and rated PG. However, this is not the alternate PG version which was released in 1973. It runs the same amount of time like the original 1970 version and none of the aforementioned scenes were removed from this VHS release and "Suicide is Painless" was still the main theme used. The actual 1973 PG edited version, has never been released on any video formats in the United States.