Casting | Rôle |
|---|
| Lew Ayres | Dr. James Kildare |
| Lionel Barrymore | Dr. Leonard Gillespie |
| Laraine Day | Nurse Mary Lamont |
| Shepperd Strudwick | Dr. Gregory 'Greg' Lane |
| Samuel S. Hinds | Dr. Stephen Kildare |
| Emma Dunn | Mrs. Martha Kildare |
| Nat Pendleton | Joe Wayman, Ambulance Driver |
| Walter Kingsford | Dr. S.J. 'Walter' Carew, Hospital Administrator |
| Alma Kruger | Molly Byrd, Superintendant of Nurses |
| John Eldredge | Henry Adams, Amnesia Patient |
| Nell Craig | Nurse 'Nosey' Parker |
| Marie Blake | Sally, Hospital Switchboard Operator |
| Charles Waldron | Dr. 'Egghead' Squires, Messinger Inst. |
| George Lessey | Rufus Ingersoll |
| Tom Collins | Dr. Joiner |
| George H. Reed | Conover, Gillespie's Attendant |
| Paul Porcasi | Antonio 'Tony', the Hospital Chef |
| Horace McMahon | J. Harold 'Fog Horn' Murphy |
| Frank Orth | Mike Ryan, Sullivan's Hospital Cafe |
| Margaret Seddon | Mrs. Julia Cray, Skin Alergy Patient |
| Fay Helm | Mrs. Henry Adams |
| William Bailey | Spectator in Operating Theatre (uncredited) |
| Stephen Chase | Ambulance Interne (uncredited) |
| Donald Douglas | Mr. Grayson, Patient losing Eye Sight (uncredited) |
