Dr. Jack

Harold Lloyd

Dr. 'Jack' Jackson

Mildred Davis

The Sick-Little-Well-Girl

John T. Prince

Charles F. Haskell - Her Father

Eric Mayne

Dr. Ludwig von Saulsbourg

C. Norman Hammond

Jamison - the Lawyer

Jackie Condon

Boy's Pal (uncredited)

Mickey Daniels

Boy Patient (uncredited)

Richard Daniels

Man (uncredited)

William Gillespie

Card Player (uncredited)

Wally Howe

Asylum Guard (uncredited)

James T. Kelley

Card-Playing Father (uncredited)

'Auntie' Mackay

Undetermined Secondary Role (uncredited)