John Merivale
Dr. John Fielding
Didi Sullivan
Ellen Fielding
Vittorio André
Prof. Rodriguez
Nerio Bernardi
Police Inspector
Giacomo Rossi Stuart
Prof. Rodriguez's Assistant
Mario Bava
Mexican at police station (uncredited)
Renzo Palmer
Narrator (voice)
Leslie Daniels
Prof. John Fielding (voice)
Renato De Carmine
Prof. John Fielding (voice)
Stefano Sibaldi
Max Gunther (voice)
Michele Malaspina
Prof. Rodriguez (voice)