Producer Donald E. McCoy strongly disagreed with the use of nuclear warheads. He only agreed to finance the film if Edward D. Wood Jr. rewrote his original script, and made it end with a nuclear explosion as a warning against the use of nuclear weapons.
According to Paul Marco, Edward D. Wood Jr. thought that Bela Lugosi's memory might not be very good, so for Lugosi's long speech, Wood had the prop man make cue cards. Lugosi, upset, insisted he didn't need cue cards and he would "memorize it." Wood still insisted on the cue cards, telling Lugosi, "We have to be safe". Lugosi went to Marco for help. He had Marco promise not to show him the cue cards during the scene. Marco held the cards at his side the whole time and Lugosi never looked over once. After Lugosi's performance the whole crew got up and applauded.
The prop octopus was stolen from Republic Studios and was constructed for the John Wayne film Wake of the Red Witch (1948). The motor which controlled the octopus' tentacles was not stolen with it, as is obvious to the casual viewer. Additionally, one of the tentacles was torn off in the process of stealing it out of the property room.
Edward D. Wood Jr. began shooting this film - then called "Bride of the Atom" - in October 1954 on a tiny sound stage in Los Angeles called Ted Allan Studios. He ran out of money after just three days and had to shut down production.
Tony McCoy was cast in the male lead role, primarily because his father, Arizona entrepreneur Donald E. McCoy, was the owner of Packing Service Corp. (a meat packing concern), and was a major investor in the film.
Contrary to popular legend, Bela Lugosi cannot be seen fighting the rubber octopus in the sump (filmed in Griffith Park). Close examination of the scene reveals a stunt double doing battle. In fact, all the shots of Vornoff carrying Janet through the brush and moving down the hill, reveal a stunt double for Lugosi. Even the real close-ups of Lugosi during these sequences appear to have been shot on a stage with black backing.