Captain John Yossarian, a U.S. Army Air Force B-25 bombardier, is stationed on the Mediterranean base on Pianosa during World War II. Along with his squadron members, Yossarian is committed to flying dangerous missions, but after watching friends die, he seeks a means of escape.
Futilely appealing to his commanding officer, Colonel Cathcart, who continually increases the number of missions required to rotate home before anyone can reach it, Yossarian learns that even a mental breakdown is no release when Doc Daneeka explains the “Catch-22” the Army Air Corps employs.
While most crews are rotated out after twenty-five, the minimum number of missions for this base is eventually raised to an unobtainable eighty missions; a figure resulting from Colonel Cathcart’s craving for publicity. Compliance with this insane number invokes regulation 22 for which, as explained by Doc Daneeka, there is a catch: An airman would have to be crazy to fly more missions, and if he were crazy he would be unfit to fly. Yet, if an airman would refuse to fly more missions, this would indicate that he is sane, which would mean that he would be fit to fly the missions.
Another strange “catch” in the movie involves Major Major, who had recently been promoted by Brigadier General Dreedle, who didn’t like the look of the name “Capt. Major” on the roll call. Capt. Major was promoted to Major Major and put in charge of a squadron, very much against his will. Major didn’t want to be bothered, so he told First Sgt. Towser that if someone wanted to talk to Major Major, the person had to wait in the waiting room until office hours were over, unless Major wasn’t in his office. Then the visitor could go right in, but Major wouldn’t be there.
Trapped by this convoluted logic, Yossarian watches as individuals in the squadron resort to unusual means to cope; Lt. Milo Minderbinder concocts elaborate black market schemes while crazed Captain “Aarfy” Aardvark commits murder to silence a girl he raped. Lieutenant Nately falls for a prostitute, Major Danby delivers goofy pep talks before every bomb run and Captain Orr keeps crashing at sea. Meanwhile, Nurse Duckett occasionally beds Yossarian.
Nately dies as a result of an agreement between Milo and the Germans, trading surplus cotton in exchange for the squadron bombing its own base. While on a pass, Yossarian shares this news with Captain Nately’s Whore, who then tries to kill him.
Because of Yossarian’s constant complaints, Colonel Cathcart and Lt. Colonel Korn eventually agree to send him home, promising him a promotion to Major and the awarding him a medal for the fictitious saving of Cathcart’s life; the only requirement being that Yossarian agrees to “like” the Colonels and praise them when he gets home.
Immediately after agreeing to Cathcart’s and Korn’s plan, Yossarian survives an attempt on his life when stabbed by Nately’s Whore, who had disguised herself as an airman. Once recovered, Yossarian learns from the Chaplain and Major Danby that Captain Orr’s supposed death was a hoax and that Orr’s repeated ‘crash’ landings had been a subterfuge for practicing and planning his own escape from the madness. Yossarian is informed that after his last ditching Orr had paddled a rescue raft all the way to Sweden.
Yossarian decides to ditch the deal with Cathcart, leaps out of the hospital window, takes a raft from a damaged plane and, while a marching band practices for the ceremony to award Yossarian the promotion and medal, he hops into the sea, climbs into the raft and starts paddling.