- Backed by the Pentagon: The helicopter sequences were filmed at Camp Pickett in Virginia, where MASH personnel trained before being sent to Korea. The commander of the base was generously accommodating to the production team, offering the use of his house to the lead actors. The film's technical advisor, Col. K. E. Van Buskirk, commanded one of the first MASH units in the Korean War, which was still ongoing when the film was released.
- California Doubling: In addition to the above-mentioned sequences filmed in Virginia, principal photography took place in Calabasas, California.
- Creator Backlash: Humphrey Bogart did not enjoy filming the movie, not the least because he burned his thumb in one scene. At the end of filming, he told director Richard Brooks "Let's not make any more movies together".
- Executive Meddling: The film was originally titled MASH 66, but MGM forced a name change out of concerns that audiences wouldn't understand the meaning of the name.
Trivia / Battle Circus