The 4077th Mobile Army Surgical Hospital is stuck in the middle of the Korean war. With little help from the circumstances they find themselves in, they are forced to make their own fun. Fond of practical jokes and revenge, the doctors, nurses, administrators, and soldiers often find ways of making wartime life bearable.
Margaret, calling from Tokyo, holds the camp in suspense until she returns with the news of her engagement to Lieutenant Colonel Donald Penobscott. Frank Burns takes the news hard and arrests a Korean family as spies.
Following an offer of promotion made by Master Sergeant Woodruff at a poker game, Radar is promoted to the rank of lieutenant. Finding this position awkward, Radar opts to return to his position as an enlisted man.
The nurses go behind Margaret's back so that a fellow nurse confined to her tent can spend the night with her soldier husband who is paying her a surprise visit.
Margaret takes off in the middle of the night to help deliver a Korean baby. Nobody knows of her whereabouts, and Colonel Flagg is brought in to help investigate her disappearance.
Psychiatrist Sidney Freedman composes a letter to Sigmund Freud during a visit to the 4077, while the rest of the camp endures the hijinks of a mystery prankster.
Hawkeye and Potter provide assistance at a Korean clinic, and run into an enemy attack on the way home. Meanwhile, Klinger begins posing as a Gypsy to help get his discharge papers.
Everybody pitches in to save Colonel Potter's horse, who becomes sick while Potter is away in Tokyo. And Margaret asks Hawkeye, not Frank, to operate on her appendix.
To save the life of an elderly local who rejects an operation because he believes bad spirits surround the 4077th, Colonel Potter permits a Korean exorcism.
Radar becomes an aspiring writer after ordering a flier from a comic book, and Hawkeye and B.J. give Frank a surprise birthday present that only he will appreciate.
The 4077th hosts a traditional Korean wedding, much to Frank's objections. And Colonel Potter runs into an old friend who has put his troops in jeopardy so that he could receive a promotion.
A former star college football player suffers a severe leg injury in combat and must deal with the consequences, and Major Burns goes behind Colonel Potter's back to set up a boxing match between Klinger and Zale.
B.J. falls off the fidelity wagon while trying to provide consolation to a nurse whose marriage has just ended. But will he confess his infidelity to his wife?
General Korshak wants Hawkeye to be his personal practitioner, despite his constant snottiness. And Radar helps take care of a soldier's half-Korean baby after he is shipped back home.
Colonel Potter hopes a Western will be the cure for the 4077th's morale problem. But during the show, the staff of the camp is forced to make its own entertainment during the frequent film breakages.
Hawkeye and BJ try to stop a chopper pilot from selling souvenirs derived from war materials derived from locals facing danger getting them, and Klinger becomes a pole-sitter in his latest attempt to get a Section Eight.
Pressured by Frank, Margaret decides to marry Colonel Donald Penobscott at the 4077th. When Donald arrives in camp, he is treated to a bachelor party and a practical joke while the nurses give Margaret a bridal shower.