Originally, the two leads (who appropriately spend the movie mixing up their own names) were cast the other way around.
Richard Dreyfuss' part was to be played by Sir Sean Connery, who abandoned the film for a bigger paycheck in Jagd auf Roter Oktober (1990).
This movie is based on the original Broadway production of "Rosencrantz and Guildenstern Are Dead" by Sir Tom Stoppard and opened on October 9, 1967 at the Alvin Theater, ran for 420 performances and won the 1968 Tony Award for Best Play.
The opening song at the beginning of the movie is Pink Floyd's "Seamus" (Meddle, 1971). The version included in the movie is an instrumental version. The album version has vocals. During the theatre company's performance of pseudo-Hamlet, a sound bit from Pink Floyd's "Echoes" (also from Meddle, 1971) can be heard. The sound of the rapier sword is the first note heard in "Echoes".