• 
  William Dieterle

  regizor

• 
  Sheridan Gibney

  scenarist

• 
  Paul Muni

  Dr. Louis Pasteur
• 
  Akim Tamiroff

  Dr. Zaranoff
• 
  Josephine Hutchinson

  Marie Pasteur
• 
  Anita Louise

  Annette Pasteur
• 
  John Picorri
• 
  Eric Mayne

  Lord Chamberlain

• 
  Dickie Moore

  Joseph Meister
• 
  Mabel Colcord

  A Lady
• 
  Donald Woods

  Dr. Jean Martel
• 
  William Burress

  Doctor
• 
  Brenda Fowler

  Midwife
• 
  Porter Hall

  Dr. Rossignol
• 
  Frank Reicher

  Dr. Pfeiffer

• 
  Edward Van Sloan

  Chairman
• 
  Frank Mayo

  Sadi Carnot
• 
  Henry O'Neill

  Dr. Emile Roux
• 
  Halliwell Hobbes

  Dr. Lister
• 
  George Beranger

  Assistant
• 
  Walter Kingsford

  Napoleon III
• 
  Richard Alexander

  Burly farmer
• 
  Bill Elliott

  Reporter
• 
  Tempe Pigott

  Woman