 | John Nesbitt als Narrator (voice) |
 | Shepperd Strudwick als Dr. Semmelweis |
 | Rudolph Anders als Doctor (uncredited) |
 | King Baggot als Passerby (uncredited) |
 | William Bailey als Passerby (uncredited) |
 | Barbara Bedford als Nun Reading Book (uncredited) |
 | Ralph Brooks als Medical Student at Lecture (uncredited) |
 | Mary Howard als Young Stricken Mother (uncredited) |
 | Leonard Penn als Semmelweis' Assistant (uncredited) |
 | Beatrice Roberts als Passerby (uncredited) |
 | Edward Van Sloan als Hospital Chief of Staff (uncredited) |
 | E. Alyn Warren als Professor (uncredited) |
| Fred Zinnemann | Director |
| Herman Boxer | Screenplay |
| David Snell | Music |
| Leonid Raab | Orchestrator |
| Harold Rosson | Director of Photography |
| George Bassman | Orchestrator |
| John Nesbitt | Producer |
