Captain Josiah Newman runs the neuro-psychiatric ward of an Arizona desert hospital during World War II. He often uses unconventional means and people to match, including his new orderly, Jackson Leibowitz. Among the patients in their ward is the suicidal Colonel Bliss, who eventually climbs atop a water tower, and a battle-scarred corporal named Tompkins who reveals under the spell of sodium pentothal the source of his distress. Newman also assists in the marital love life of Captain Winston while enjoying a flirtation or two with his own chief nurse, Lieutenant Corum.

The Marx Brothers help young Broadway hopefuls when they get mixed up with gangsters due to a tin of sardines containing Romanoff diamonds.