Cantinflas as Salvador Medina / Chava

Marta Romero as Laura Villanueva

Miguel Ángel Álvarez as Dr. Miguel Villanueva

Prudencia Grifell as Señora Martínez

Wolf Ruvinskis as Papá de Beto

Guillermo Zetina as Dr. Marín

Tony Carbajal as Dr. Pablo Montero

Pepito Velázquez as Beto

Carlos Riquelme as Administrador del hospital

Rosa Elena Durgel as Mamá de Beto

Alberto Catalá as Paciente ambidextro

Consuelo Monteagudo as Suegra de neurótica

José Chávez as Isidro Martínez

Paz Villegas as Paciente viejita coqueta

Ada Carrasco as Doña Lola

Arturo Castro 'Bigotón' as Comisario del pueblo

Guillermo Bravo Sosa as Paciente malnutrido (uncredited)

Margarita Delgado as Enfermera (uncredited)

Pedro Elviro as Paciente con television (uncredited)

Carmelita González as Paciente neurótica (uncredited)

Ramón Valdés as Paciente vendado (uncredited)

Alejandro Suárez as Hippie en cantina (uncredited)

Alfonso Zayas as Hippie en cantina (uncredited)

Jorge Zamora as Hombre en cantina (uncredited)