The hair for the Peking Man suit used in the film was made from actual human hair. A total of 300 Hong Kong citizens arrived at the studio to donate.
Evelyne Kraft performed her own stunts in the film.
In the film, special effects artist Keizô Murase donned the Peking Man suit after the original stuntman refused to be lit on fire for a scene. Murase personally doused himself with the oil that would be used to light him on fire, then allowed himself to be lit on fire and leaped from the building to crash onto the miniature below. He did this for a total of three takes. Murase would sustain injuries, as the miniatures were made of wood, cement and glass. He received a gold watch from the film's producer as payment.
While filming a scene in the film outside on location in India where crowds of extras were supposed to be acting scared of the Peking Man, the men kept staring at Evelyne Kraft in her skimpy fur bikini, then their wives slapped them in their faces. It kept happening over and over again, so the film crew kept having to shoot the same scene over and over again until they finally got it right.
The miniature vehicles used in the film were custom built on a 1/25 scale.