Elwood P. Dowd is an affable man who claims to have an unseen (and presumably imaginary) friend Harvey — whom Elwood describes as a six-foot, three-and-one-half-inch tall pooka resembling an anthropomorphic rabbit. Elwood introduces Harvey to everyone he meets. His social-climbing sister, Veta, increasingly finds his eccentric behavior embarrassing. She decides to have him committed to a sanitarium. When they arrive at the sanitarium, a comedy of errors ensues. Only just before Elwood is to be given an injection that will make him into a "perfectly normal human being, does Veta realize that she would rather have Elwood the same as he has always been — carefree and kind — even if it means living with Harvey.
