El doctor 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)

Florence Mayon

Card Player's Daughter (uncredited)

Oscar Morgan

Undetermined Secondary Role (uncredited)

Charles Stevenson

Asylum Guard (uncredited)

Anna Townsend

Jamison's Mother (uncredited)