Filming began on June 24, 1938 and was completed on October 19, 1938.
The film premiered in Los Angeles on January 24, 1939.
California's Sierra Nevada range, Alabama Hills and surrounding areas doubled as the Khyber Pass for the film.

Douglas Fairbanks, Jr. reported in a featurette interview on the DVD release that in his travels, he has met several Hindi Indians who were convinced the external scenes were filmed on location in Northwest India at the actual Khyber Pass.
 A few interiors were made on sets at RKO Radio Pictures Hollywood sound stages, and one exterior scene filmed on the RKO Encino movie ranch.
 The original script was composed largely of interiors and detailed life in the barracks.
The decision was made to make the story a much larger adventure tale, but the re-write process dragged on into principal shooting.
Some of the incidental scenes that flesh out the story were filmed while hundreds of extras were in the background being marshaled for larger takes.

The movie includes a sequence at the end in which a fictionalized Rudyard Kipling, played by Reginald Sheffield, witnesses the events and is inspired to write his poem (the scene in which the poem is first read out carefully quotes only those parts of the poem that tally with the events of the movie).
Following objections from Kipling's family, the character was excised from some prints of the movie, but has since been restored.
Filming began on June 24, 1938 and was completed on October 19, 1938. The film premiered in Los Angeles on January 24, 1939. California's Sierra Nevada range, Alabama Hills and surrounding areas doubled as the Khyber Pass for the film.
Douglas Fairbanks, Jr. reported in a featurette interview on the DVD release that in his travels, he has met several Hindi Indians who were convinced the external scenes were filmed on location in Northwest India at the actual Khyber Pass.  A few interiors were made on sets at RKO Radio Pictures Hollywood sound stages, and one exterior scene filmed on the RKO Encino movie ranch.  The original script was composed largely of interiors and detailed life in the barracks. The decision was made to make the story a much larger adventure tale, but the re-write process dragged on into principal shooting. Some of the incidental scenes that flesh out the story were filmed while hundreds of extras were in the background being marshaled for larger takes.
The movie includes a sequence at the end in which a fictionalized Rudyard Kipling, played by Reginald Sheffield, witnesses the events and is inspired to write his poem (the scene in which the poem is first read out carefully quotes only those parts of the poem that tally with the events of the movie). Following objections from Kipling's family, the character was excised from some prints of the movie, but has since been restored.
Gunga Din (film)