Contrary to popular belief, the detective who points his gun at himself several times did so deliberately. The actor was actually testing director Edward D. Wood Jr. to see if he would notice. Needless to say, Ed Wood didn't notice.
Bela Lugosi appears in footage shot just before his death, but with no script in mind. Edward D. Wood Jr. wrote the script to accommodate all the footage shot in a cemetery and outside Tor Johnson's house in the new production. Lugosi was doubled by Tom Mason, Wood's wife's chiropractor, who was significantly taller than Lugosi, and played the part with a cape covering his face.
One of the legends about the production of this film was that Edward D. Wood Jr. used everything from automobile hubcaps to pizza pans to pie tins and even paper plates as flying saucers. The truth is that he bought a number of the Lindberg 1/48 scale "Flying Saucer" plastic model kits for use as props. One was modified with a wooden block, to represent the squared walled flying saucer set (the UFO seen landing in the graveyard).
Footage from the same shoot that produced Bela Lugosi's performance in this movie was meant to be used to make another film, "The Ghoul on the Moon". When Edward D. Wood Jr. went to retrieve the film he found it had been ruined, so the new movie was scrapped.
Copies of the original 35mm release prints are extremely rare. There were reportedly fewer than 20 release prints struck for the original release. As part of the distribution deal with the Distributors Corporation of America (DCA), producer J. Edward Reynolds had to pay for the release prints and advertising material.
Previewed as "Grave Robbers from Outer Space" at the Carlton Theater in Los Angeles on March 15, 1957, the film went into general release as "Plan 9 from Outer Space" in July of 1959, on a double bill with the British suspense thriller Time Lock (1957), which featured a pre-James Bond Sean Connery. The actual copyright for the film is 1957.
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 (1988) 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.
Although some saw the insertion of footage of the recently deceased Bela Lugosi into the film as exploitation, in his autobiography Edward D. Wood Jr. saw it as a homage to the actor. In the last few years of his life, Lugosi had become a firm friend of the director.
Much of the filming took place at an independent soundstage called Quality Studios. Though it hasn't been used as a soundstage for many years, the building still exists. It is located on Santa Monica Blvd. near Western Ave. The entranceway is located next to the Harvey Hotel.
Although trade publications announced the movie's general release in July 1959, distributor DCA had already made prints available to cinemas from June 1958 onwards, with the film playing on regular movie theatre bills in states as far afield as Maryland, New Mexico, Ohio, Rhode Island and Texas during the 13 months prior to its supposed "general release".
John Breckinridge', who played the alien ruler, and his secretary David DeMering, who played Gregory Walcott's co-pilot, were cast in the film because they happened to be house-guests of actor Paul Marco at the time. Marco played Officer Kelton.