This film marks the first collaboration between Mario Bava and his son/assistant director Lamberto Bava. Lamberto would later become a director himself.
Director Mario Bava used the mirror-based Schufftan Process to combine live action with miniatures and thereby avoiding the costly matte/optical printing techniques.
Only one spaceship model was built for this film.
This film went through fifteen working titles before American International Pictures settled on "Planet of the Vampires."
Susan Hart was originally cast as Sanya, but upon arriving in Rome immediately following her honeymoon with AIP co-founder James H. Nicholson, she was locked out of production due to Samuel Z. Arkoff's enforcement of a new anti-nepotism company policy. Hart also suspects that Barry Sullivan's on-set arguments with an unidentified production member was another factor in her dismissal. Norma Bengell was not cast as her replacement until halfway through shooting. Hart would later appear in another Mario Bava film, Bonecas Explosivas (1966), although her only scene in the film was recycled from its predecessor, A Máquina de Fazer Bikini (1965).