Juanita Hall, who had played Bloody Mary in the original Broadway production, obviously sang her own songs onstage, but was dubbed in the film version at the request of composer Richard Rodgers. Rodgers and musical director Alfred Newman brought in Muriel Smith (who had played Bloody Mary in London).
The film ran for just under 4½ years at the Dominion Theatre in London. It opened April 21, 1958 and closed September 30, 1962, for a record run that probably will never be equaled.
Tonkinese (Vietnamese) character "Bloody Mary" was played by Juanita Hall, who was black. She was reprising her role from the Broadway show. She would later be cast as a Chinese woman in Flower Drum Song (1961).
Dating back to the development of the stage musical, Richard Rodgers and Oscar Hammerstein II were pressured to eliminate the song "You've Got To Be Carefully Taught", but they resisted. The movie was greeted with objections and even boycotts in certain parts of the country specifically because of the song.
This is the only theatrical film adaptation of a Richard Rodgers and Oscar Hammerstein II stage show to have all the songs intact, with the addition of the song "My Girl Back Home", which was cut from the play before it opened.