Writer and director Peter Ustinov provided the voices of all of the U.N. delegates in the opening scene.
This movie contains the only screen acting performance of Maria, Baroness Budberg, a Russian aristocrat who fled her homeland at the time of the revolution in 1917, and never returned to it. In the west, she was famous as a translator of Chekhov and other Russian writers, and as the mistress of Maxim Gorki and H.G. Wells.
Suzanne Cloutier (Marfa Zlotochienka) was the real life wife of the star, writer and director Peter Ustinov (The General) from 1954 to 1971.
The original Broadway production of "Romanoff and Juliet" by Sir Peter Ustinov opened at the Plymouth Theater in New York City on October 10, 1957, ran for three hundred eighty-nine performances, and was nominated for the 1958 Tony Award for the Best Play. Peter Ustinov and Edward Atienza re-created their stage role in the film and Ustinov was nominated for the 1958 Tony Award for Best Actor in a Play.