The film was a low budget production as Lombardo did not care for horror films. Freda and his crew utilized mostly existing sets with only a single scene at the Aniene river filmed outside the studio. The film was shot in black-and-white by cinematographer Mario Bava, who felt that that style would better suit the special effects in the film and keep the budget down. Bava worked on the special effects on the film without credit. One of his effects involved Gianna Maria Canale aging make-up that would only be revealed when certain coloured lights were revealed on her. This effect had been done previously in older films, such as "Dr. Jekyll and Mr. Hyde" (1931) and contemporary films, including "The Man Who Turned to Stone" (1957). Freda's deal with his producers failed when he left the set on the 12th day of production. After an argument with the producers, Freda left the production allowing Mario Bava to step in to finish the film in the next two days. Reasons for Freda leaving production differ and range from Freda having a misunderstanding with the producers to Bava stating that Freda was taking too long to make the film. Bava's ending was different than Freda's initial ending, which involved finding the heroine hanged. Among the changes Bava made to finish the film included changing the supporting character of the journalist becoming the lead and removing a subplot about a dismembered criminal who returns to life on being reassembled. Bava also extended other portions of the film with stock footage and montages of newspaper presses. "I Vampiri" was released in Italy on 5 April 1957 in San Remo. It grossed a total of 125.3 million Italian lire on its initial theatrical run. The film was not a box office success in either Italy or France. It was released in the U.S. in 1960 in a heavily altered version under the title "The Devil's Commandment". This version of the film featured new scenes written by J. V. Rhems and filmed by Ronald Honthauer in New York. In the United Kingdom, the film was released under the title "Lust of the Vampire". Mario Bava biographer Tim Lucas wrote in 1992 that another version of the film, also titled "Lust of the Vampire", was assembled in the U.S., which incorporated scenes of nudity. A photonovel version of "I Vampiri" was released in Italy.