The year after this film was released the owner of a prosperous theater chain hired an architect who designed a mansion that was inspired by the Shangri-La lamasery in this film. Located in Denver, Colorado, it still exists today.
Decades ago, when the film was shortened for viewing on television, some 25 minutes of footage was deleted, reducing the length to 107 minutes. In the years following UCLA tried to reconstruct the film, using the complete 123-minute soundtrack. Most of the missing film was badly degraded and useless, so the restorers used stills to fill in the missing minutes. Later, one minute of the missing footage was found and restored, resulting in some 24 minutes of stills supported by the soundtrack. The one minute of restored footage depicts Conway's meeting with the High Lama.
In 1937, at a test screening of the 210-minute version, Frank Capra experienced inappropriate laughter and mass walkouts from the audience. In an interview on The Dick Cavett Show (1968) (available on DVD), Capra explained he was so perturbed by the screening that he spent two days walking around Lake Arrowhead, trying to figure out why the film hadn't worked. He finally decided to remove the first two reels' worth of footage (about 20 minutes), changing nothing else, and showed it again. This time the test audience loved it. He was so happy to have discovered the problem with the film that he took the excised original footage and threw it onto a fire. (His account is disputed by editor Gene Milford, who notes that burning the nitrate film would have caused a large explosion.)
Soundman Edward Bernds came up with the idea of achieving a faster, barbaric tempo for the previously slow-moving refueling scene by having the tribesmen stab the tops of the gasoline cans with their bayonets and slosh the gasoline out. Frank Capra liked the idea and included it.
Sondra and Lovett do not appear in James Hilton's novel. They were added to the screenplay for romantic interest and comic relief.