Harold Lloyd as Dr. 'Jack' Jackson

Mildred Davis as The Sick-Little-Well-Girl

John T. Prince as Charles F. Haskell - Her Father

Eric Mayne as Dr. Ludwig von Saulsbourg

C. Norman Hammond as Jamison - the Lawyer

Jackie Condon as Boy's Pal (uncredited)

Mickey Daniels as Boy Patient (uncredited)

Richard Daniels as Man (uncredited)

William Gillespie as Card Player (uncredited)

Wally Howe as Asylum Guard (uncredited)

James T. Kelley as Card-Playing Father (uncredited)

'Auntie' Mackay as Undetermined Secondary Role (uncredited)

Florence Mayon as Card Player's Daughter (uncredited)

Oscar Morgan as Undetermined Secondary Role (uncredited)

Charles Stevenson as Asylum Guard (uncredited)

Anna Townsend as Jamison's Mother (uncredited)

Dorothy Vernon as Restaurant Hostess (uncredited)

Joy Winthrop as Undetermined Secondary Role (uncredited)