 Harold LloydDr. 'Jack' Jackson | Dr. 'Jack' Jackson |
 Mildred DavisThe Sick-Little-Well-Girl | The Sick-Little-Well-Girl |
 John T. PrinceCharles F. Haskell - Her Father | Charles F. Haskell - Her Father |
 Eric MayneDr. Ludwig von Saulsbourg | Dr. Ludwig von Saulsbourg |
 C. Norman HammondJamison - the Lawyer | Jamison - the Lawyer |
 Jackie CondonBoy's Pal (uncredited) | Boy's Pal (uncredited) |
 Mickey DanielsBoy Patient (uncredited) | Boy Patient (uncredited) |
 Richard DanielsMan (uncredited) | Man (uncredited) |
 William GillespieCard Player (uncredited) | Card Player (uncredited) |
 Wally HoweAsylum Guard (uncredited) | Asylum Guard (uncredited) |
 James T. KelleyCard-Playing Father (uncredited) | Card-Playing Father (uncredited) |
| ''Auntie' MackayUndetermined Secondary Role (uncredited) | Undetermined Secondary Role (uncredited) |
| FFlorence MayonCard Player's Daughter (uncredited) | Card Player's Daughter (uncredited) |
| OOscar MorganUndetermined Secondary Role (uncredited) | Undetermined Secondary Role (uncredited) |
 Charles StevensonAsylum Guard (uncredited) | Asylum Guard (uncredited) |
 Anna TownsendJamison's Mother (uncredited) | Jamison's Mother (uncredited) |
 Dorothy VernonRestaurant Hostess (uncredited) | Restaurant Hostess (uncredited) |
| JJoy WinthropUndetermined Secondary Role (uncredited) | Undetermined Secondary Role (uncredited) |
