Serpiente de mar

Timothy Bottoms

— Pedro Fontán

Taryn Power

— Margaret

Jared Martin

— First Mate Lemaris

Ray Milland

— Professor Timothy Wallace

Gérard Tichy

Carole James

— Jill

Jack Taylor

— Hospital Killer

León Klimovsky

— Dr. Moore

Charly Bravo

Víctor Israel

— Porto, Night Watchman

Pilar Alcón

— Nurse (as Diana Eagle)

José Canalejas

Eduardo Bea

Teresa del Olmo

Alicia González

José Yepes

Jorge Bosso

Beatriz Savón

José Bastida

Barta Barri

— Defensor

Paco Catalá

Fabián Conde

Alfonso de la Vega

Alfredo Enríquez

José Ramón Pardo

Luís Zagalo

Miguel de Grandy

Paul Benson