3 Wayne RogersWayne Rogers played "Trapper" John alongside Alan Alda's "Hawkeye" in the first three seasons of MASH. Rogers passed on auditioning for Hawkeye in favor of Trapper, finding the character's less cynical personality more appealing. However, as Alda's popularity with audiences grew, the focus shifted more towards Hawkeye, leaving Rogers feeling sidelined. He decided to quit, and his character was written out in the season 4 premiere, with Trapper being discharged offscreen, leaving no goodbye notes for best friend Hawkeye. Rogers went on to roles in shows like the medical sitcom House Calls, which lasted three seasons.

2 Larry LinvilleLarry Linville played Major Frank Burns, a memorably nasty villain on MASH. Burns was judgmental, self-absorbed, selfish, and strictly by the book, making him widely despised by the 4077th. Linville decided to leave MASH after five seasons, growing bored with playing such a weaselly character. Burns' exit is explained in the season 6 premiere, where he is sent back to the States for a psychiatric evaluation after a drunken night out in Seoul. The unit is overjoyed by the news he's gone for good.

1 Gary BurghoffGary Burghoff, the only real holdover from the MASH movie, played Corporal "Radar" O'Reilly in both the movie and series. Radar was a much more naive and innocent figure in the series, becoming a favorite among audiences. Burghoff decided to leave MASH during season 8 due to exhaustion from the show's schedule. Radar's exit is one of the most emotional on the show, as he is given a hardship discharge to go back to his family farm following a death in the family.

Burghoff went on to guest roles on shows like The New Adventures of Wonder Woman and Fantasy Island. In a solo spinoff called W*A*L*T*E*R, the character becomes a policeman. While the spinoff did not materialize past the pilot, Burghoff continued with guest appearances on AfterMASH.