The alien costume featured here was the same as the one used in another Roger Corman film, Teenage Cave Man (1958). This was done to save money, as Corman and his brother Gene Corman often tried to incorporate existing sets, costumes and other elements from previous films into new ones for financial savings. Screenwriter Martin Varno said the Corman brothers were so conscious of their spending that "'cheap' was the main word in their vocabulary". The monster costume scenes in "Teenage Caveman" and this film were shot within about two weeks of each other. The costume was modified slightly for this film. Ross Sturlin wore the costume for the scenes in both "Teenage Caveman" and this film. Flming was very difficult for Sturlin because it got extremely hot inside the costume during the exterior shots. John John M. Nickolaus Jr. was director of photography for the film, and Jack Bohrer was the production manager. Daniel Haller, who went on to become a film director himself, worked as art director on this film. He did much of the manual construction work on the set himself, and brought a trailer in to the sound stage so he could sleep there and between work sessions. Among the props he built was the rocket-ship, the frame, which was made of plywood that had been cut into circles, then covered with a plastic sheet and spray-painted to look metallic. Haller also created blood cells that the characters looked at under a microscope, and the baby aliens (which resembled seahorses) they looked at under a fluoroscope. Alexander Laszlo composed the music for the film. Almost the entire crew went on to work on Attack of the Giant Leeches (1959) with the Corman brothers and Kowalski.
This was released in one of American-International's prepackaged double features. It was paired with Roger Corman's She Gods of Shark Reef (1958), which had been sitting on the shelf for 18 months.
With a budget of about $68,000, it was shot over seven days. All of the interior scenes were shot at sound stages inside Kling Studios. Most of the exterior shots were filmed at Bronson Canyon, a set of caves at Griffith Park in Los Angeles that was a popular location for low-budget films. The exterior scenes of the tracking station were shot at a television station on Mt. Lee, not far from the Hollywood Sign. Screenwriter Martin Varno said it was the first television station built in Los Angeles, but was only being used for emergency broadcasts when this film was being shot there; it had also been used during World War II to broadcast to allied fores overseas. Varno secured permission to film there simply by calling Los Angeles city officials and asking, something he said nobody else considered trying because they assumed the city would not allow it. Varno was familiar with the station because his father, Roland Varno, appeared in the first dramatic television show released in Los Angeles and it was transmitted from that station. For this film, Los Angeles charged a fee of $8 per actor to shoot at the station, but the crew could be any size. All shooting took place outside the station. Most of the night scenes shot there were shot during the day, and the crew often had to find shadows to shoot in or block out the sun to give the impression of nighttime. Producer Gene Corman said of the shooting: "That was one of the more mobile units I've ever been involved with. Normally, everybody chases the sun; we were chasing the shadows."
When star Ed Nelson was asked what he remembered about the film during a 2003 interview, he admitted, "Not much", but he said that Roger Corman and Gene Corman] were very knowledgeable about film and treated the material "light-heartedly".
The film was featured in a 1996 episode of the comedy television series Mystery Science Theater 3000 (1988).