Final film of Hugh Beaumont.

Spoofed on episode 20, season 4 of Mystery Science Theater 3000.

The Human Duplicators was shown in the US on a double bill with Mutiny in Outer Space.

The Human Duplicators' interior shots were filmed at Producers Studio in Hollywood. Exterior locations were Bronson Canyon in Griffith Park in Los Angeles and a school located at 5210 Clinton St. in LA, which was used as the Space Research Corp. building where the scientists work. The exact dates of filming could not be found, but the film was copyrighted by Hugo Grimaldi Productions on 21 October 1964.

Richard Kiel's name was not included on the movie poster for some unknown reason, although the packaging of a VHS tape of unknown date identifies the film's stars as "Richard 'Jaws' Kiel and Hugh 'Ward Cleaver' Beaumont."

Phil Hardy, the British film scholar, calls the movie a "confused and over-ambitious offering from Grimaldi." He says that The Human Duplicators "marks the beginnings of a return to the technical gimmickry of the thirties. Thus, fittingly, it stars Kiel who became one of the more bizarre jokes in the later James Bond films, which were the ultimate in technological gadgetry."

Kiel himself seems to have had mixed feelings about the film. He said in an interview with American film scholar Tom Weaver that the film "was a big hit in Chicago," where it played "in like 27 theaters" simultaneously. Kiel made personal appearances at theaters that were showing the movie in Chicago and said that they were so successful that he was asked to do the same in Toronto. But he told interviewer Maggie Howard in 2009 that "The way the director wanted me to act - kind of robotic - didn't come off as well as I would have liked."

The "Space Research Center" was the Frances Blend School from 1980 to 2016.

The film was released in the US on 3 March 1965 and at an unspecified date the same year in Canada. It opened in Mexico on 14 December 1967 as Humanoides asesinos ("Humanoids, murderers"). A day later in West Germany, where Nader was well known for playing "tough FBI agent Jerry Cotton in eight highly successful but rubbishy crime thrillers" it premiered as FBI jagt Phantom ("FBI hunts Phantom"). The movie was released to theaters in Italy as Agente Spaziale K-1 ("Space Agent K-1") and in France as Les Créatures de Kolos ("The Creatures of Kolos"). In Belgium it was shown under both the French title and the Dutch title Schepsels van Kolos ("Creatures of Kolos").The film was also released theatrically in Brazil, Greece and Spain. In France, the video version's title was Kolos, l'agent cosmique ("Kolos, the Cosmic Agent"). One of the titles used for a VHS of the movie in the US was Jaws of the Alien. Kiel appeared as the character Jaws in The Spy Who Loved Me (1977) and Moonraker (1979).

The Human Duplicators was shown as Episode 6 of Season 3 of Elvira's Movie Macabre, which first aired on 5 August 1984.