Before filming started, author H.G. Wells told everyone connected with the film how much he'd hated Fritz Lang's film Metropolis (1927) and how he wanted them to do the opposite of what Lang (whom he called "Lange") and his crew had done.
The date on the newspaper in the scene in which the war ends is September 21, 1966, which would have been the 100th birthday of H.G. Wells.
At the time of its 1947 U.S. re-release, the film was most frequently shown on the top half of a double bill, with The Man Who Could Work Miracles (1936), which likewise was based on a novel by H.G. Wells and starred Ralph Richardson on the lower half of the program.
Accurately predicts the scale and usage of large-format, flat-screen jumbo-tron style LCD television screens.
It was reported that H.G. Wells, the author of the novel on which the movie was based, actually began directing the movie, but his inexperience resulted in Director William Cameron Menzies taking over.