The company was able to get police cars and uniforms through Tor Johnson's son, Karl Johnson, an officer in the San Fernando Police Department, who also makes an uncredited appearance in the film.
The DVD release of the colorized version of the film features an audio commentary track by comedian Michael J. Nelson of Mystery Science Theater 3000 fame. The producers of the series at one point actually screened the film for airing on the show, but found it to have too much dialog to fit the show's format.
The film's original title was "Grave Robbers from Outer Space", but, supposedly, the Baptist ministers who financed the picture objected to it, so Edward D. Wood Jr. changed it to "Plan 9".
The scar worn by actor Tor Johnson had to be moved every day, as it caused severe skin irritation.
This film was shot in late 1956 and copyrighted in 1957. It took almost three years to find a distributor who would handle it.
When Gregory Walcott read the script, he told Edward D. Wood Jr. that it was the worst script he had ever read. He reluctantly signed on.