The estate of H.G. Wells was so pleased with the final production that they offered George Pal his choice of any other Wells' property. Pal chose The Time Machine.
The Flying Wing depicted in the movie is the Northrop YB-49. Two were built and both crashed. Stock footage was used in the movie.
The heat ray was burning welding wire with a blowtorch forcing the sparks off of it.
The Martian machines are always seen marching from screen right to screen left with the exception of the sequence that contains the montage of the international efforts against the Martians.
The Martian machines were models suspended from wires. For the final sequences where the machines die, they are shown crashing into telegraph poles - this allowed the filmmakers to hide the suspension wires with the telegraph wires.
The Martian war machines had about twenty wires running to each one. Some were for suspension and maneuvering, while others carried power to the various lights and mechanisms. This was produced before there were lightweight circuits and sophisticated radio controls.
The Martian war machines were originally going to be walking tripods as they were depicted in Wells's novel, but Pal didn't know how a tripod would walk and instead went with the flying machines.
The project was secured by Paramount in 1924.
The prologue of the film shows paintings of the other planets in the Solar System which the Martians examined and rejected as being unfit for habitation, finally selecting the Earth. The planet Venus, however, is neither shown or mentioned. The paintings were made by Chesley Bonestell, as famous astronomical painter whose works were often published in books on astronomy and space travel in the 1950s.
The scripture Pastor Matthew recites before he is disintegrated by the Martians is Psalms 23 from the King James version of the Bible.
The sound effects of the Martian war machines were created from three electric guitars played backwards. The sound of the Martian screaming after Forrester hit it was a mixture of a microphone scraping along dry ice and a woman's scream played backwards. The former set of sound effects became widely used stock sound effects after the film was released and were used to this day. They are still in use.
The two Martian machines that crash in Los Angeles are really the same machine from a different angle with the film image reversed.
This film had a budget of $2,000,000. Of that sum, $600,000 was spent on the live action scenes while $1,400,000 was spent on the extensive and elaborate special effects.
This film premiered on NBC television on 21 February 1967.
This is the first motion picture to film on the newly completed Harbor Freeway in Los Angeles known as The Stack. The producers got special permission to drive on it before it opened in 1953.
Two of the characters from Orson Welles's 1938 radio broadcast (portrayed in the film by different actors), Prof. Pearson (the main player in the radio broadcast), and the ill-fated journalist Carl Phillips make brief appearances at the site of the first Martian landing.
When Major General Mann first meets Dr. Forrester, he refers to an earlier meeting in Oak Ridge. This refers to Oak Ridge, Tennessee which was the home to three Manhattan Project plants which enriched and refined uranium in WWII for use in the first atomic bombs. Of the three one (K-25) was in use until 1985, and one (Y-12) is still in operation as of 2010.