Mel Brooks had problems with Yugoslavian extras who didn't speak English. In one scene, extras playing museum guards were supposed to walk through a museum, ringing hand bells and shouting, "Closing time! Closing time!" Instead, the extras misunderstood and shouted, "Cloakie Bye! Cloakie Bye!" Brooks decided "Cloakie Bye" was funnier, so he left it in the movie.
Anne Bancroft encouraged Mel Brooks to write the music as well as the lyrics for "Hope for the best, expect the worst" and subsequently at least one song for all of his movies.
Mel Brooks originally offered the role of Ippolit to Gene Wilder. But Wilder wanted to play the role of Ostap instead. Brooks refused to cast Wilder because Ostap is described in the novel as "devilishly handsome". Wilder said that he was not offended by this, but still decided not to do the film.
Marked Frank Langella's film debut. He had been recommended for the role by Anne Bancroft (wife of director/star Mel Brooks). Bancroft had appeared with Langella in William Gibson's play, "A Cry Of Players", which closed on Broadway after a brief run (November 1968-February 1969).
Mel Brooks originally announced that this would star Alistair Sim, Peter Sellers and Albert Finney. Sellers had previously been instrumental in helping Brooks' previous film, 'The Producers,' to be released.