Sacha Guitry

Character: Louis Pasteur

Maurice Schutz

Character: Grandfather

José Squinquel

Character: Émile Roux

Jean Périer

Character: Doctor

André Marnay

Character: Doctor

Pierre Labry

Character: Doctor

Armand Lurville

Character: The first witness

Camille Cousin

Character: The second witness

Henry Bonvallet

Character: Sadi Carnot, President of the Republic

Gaston Dubosc

Character: President of the Academy of Medicine

François Rodon

Character: Little Joseph Meister

Louis Maurel

Character: Jules Guérin

Louis Gauthier

Character: Poggiale

Pierre Athon

Character: Student

Pierre Huchet

Character: Servant (uncredited)

Camille Beuve

Character: Joseph Lister (uncredited)

Julien Bertheau

Character: Student (uncredited)

Gaston Allain

Character: Student (uncredited)

Félix Clément

Character: Student (uncredited)

Jean Francey

Character: Student (uncredited)

Pierre Monda

Character: Little boy (uncredited)

Charles Vissières

Character: Frémy, old doctor (uncredited)