After the success of their film "Hercules" (1958), Galatea Film began production on films in other genres that they hoped would entice the international market, which led to Riccardo Freda being hired to direct "Caltiki – The Immortal Monster". Freda left the project during filming, later explaining that he wanted to give his friend Mario Bava, who had been hired as the film's cinematographer and special effects artist, a chance to direct and earn more on the project. In interviews given long after the release of the film, both Freda and Bava gave conflicting opinions on who should be considered the real director of "Caltiki". Various historians and ministerial papers suggest that Bava did create a large amount of footage of the film involving death scenes, the monster, matching shots and special effects scenes.