M*A*S*H è una tragicommedia incentrata sulle vicissitudini del 4077th Mobile Army Surgical Hospital (Ospedale Chirurgico da Campo dell'Esercito) statunitense in Uijeongbu, Corea, durante la Guerra di Corea (1950-1953).
Molte delle situazioni raccontate, anche le più assurde, sono realmente accadute, come testimoniano molti dei veterani del conflitto.
A Greek Colonel thanks the 4077th by giving them food and drink for an Easter celebration. But the feast is foiled when softhearted Radar saves the main course from the spit - a lamb, which Radar tricks Henry into giving a medical discharge and sends home to Ottumwa, Iowa. Thus, Hawkeye and Trapper invent the famed Spam Lamb! Meanwhile, a soldier who had shot himself to get out of the army confesses to Frank, thinking he is Father Mulcahy.