This movie was originally intended to be a sequel to Goldginger (aka The Amazing Doctor G (1965)), Italian comedians Franco Franchi and Ciccio Ingrassia's Goldfinger (1964) spoof. When American International Pictures came on board as a co-financier, it was decided to shoot one movie but make two identifiably different films, one each for the Italian and English speaking markets, the Italian was to be a vehicle for the two Italian comedians and the English a Dr. Goldfoot sequel thus achieving two commercial goals of two different national investors. As such, this film was edited into two completely different movies.
This movie's Italian version's title "Le spie vengono dal semifreddo" is a parody of The Spy Who Came in from the Cold (1965). This title translates literally into English as "The Spies Who Came In from the Semi-Cold", or more commonly, "The Spies Who Came In From the Frozen Custard".
The English language version of this film was re-written, re-edited, and re-scored without the involvement of director Mario Bava whose post-production imprint was only left on the Italian language version of this film.
Dr. Goldfoot and the Bikini Machine (1965) partially parodied the James Bond movie Goldfinger (1964). This sequel was released about a year after the next James Bond movie Thunderball (1965) and also spoofed that Bond movie too as Dr Goldfoot is seen at times wearing an eye-patch like the villain Largo in Thunderball.
The Dr Goldfoot character is so named as he wears both golden pixie slippers and a black and gold jacket whilst it is alluded to briefly in Dr. Goldfoot and the Bikini Machine (1965) that Dr Goldfoot actually has golden feet.
Dr. Goldfoot and the Bikini Machine (1965) was the prequel to this movie. The only two actors and characters to reprise their roles were Dr. Goldfoot, and Bill Dexter. (Vincent Price and Fabian respectively)