Reportedly, George Pal wanted to do the final third of the movie in 3-D, starting with the sequence in which the atomic bomb is used unsuccessfully against the Martians.

Originally, the Martian War Machines were supposed to "walk" on visible electronic beams. This was attempted by having electrical sparks emanate from the three holes at the bottom of the machine. This was quickly abandoned for fear of it becoming a major fire hazard.

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.