
Members of the 4077th Mobile Army Surgical Hospital care for the injured during the Korean War and use humor to escape from the horror and depression of the situation. Among the 4077's people are Capts. Benjamin "Hawkeye" Pierce and "Trapper John" McIntire, Majs. Margaret "Hot Lips" Houlihan and Frank Burns, and Cpl. Walter "Radar" O'Reilly.

Radar gets a recorded "Dear John" letter, and the doctors try to come to his assistance with a new girl.

Hawkeye and Trapper, with an assist from Radar, make up a fictitious captain in order to donate his salary to an orphanage.

The doctors conspire to retire a gung-ho colonel whose military exploits are making the hospital busier than usual.

Frank throws his back out and applies for a Purple Heart, while Hawkeye mourns the loss of a friend and sends an underage soldier home.