The television series was created after an attempt to adapt the original novel's sequel, M*A*S*H Goes to Maine, into a film failed.

Four actors—Alan Alda, William Christopher, Loretta Swit and Jamie Farr—appeared in every one of the show's 11 seasons, while other main cast members like Wayne Rogers, McLean Stevenson, Larry Linville and Gary Burghoff were replaced over the course of the series.

The writers struggled to invent so many character names that on the seventh season, several characters were named after players from the 1978 Los Angeles Dodgers.

The outdoor set in the mountains near Malibu, California, previously used for the 1970 film, was largely destroyed by a real brush fire on October 9, 1982, just as production was wrapping; this fire was written into the finale as an enemy incendiary bombing that forces the unit to relocate.

Writer Ken Levine once got revenge on the cast for excessive script notes by rewriting an episode as a 'cold show' set in frigid Korean winter, forcing the actors to wear parkas and stand around barrel fires at the Malibu ranch when real temperatures were near 100°F (38°C).

Creators Larry Gelbart and Gene Reynolds wanted the show broadcast without a laugh track; CBS refused but agreed to omit laughter during operating room scenes, and several episodes, including most of the finale, aired with no laugh track at all.

The finale 'Goodbye, Farewell and Amen' drew a record 106 to 125 million viewers (accounts vary) and a 60.2 rating with 77 share, becoming the most-watched U.S. television broadcast of its time and remains the most-watched finale and scripted episode in American TV history.

An enduring urban legend claims New York City's water and sewage systems spiked when millions of viewers flushed their toilets right after the finale ended, a story later traced back to a similar tale about the 1930s Amos and Andy radio program.