Dame Joan Collins was originally slated to play Juliet, but turned it down when Writer and Director Renato Castellani insisted she undergo surgery to change the shape of her nose.
In 1976, several of the (by then quite elderly) costumes from this movie were rented for the Doctor Who (1963) story "The Masque of Mandragora", to the slight disappointment of Costume Designer James Acheson, who had been expecting to hire Danilo Donati's designs from Romeu e Julieta (1968), and who only discovered the mistake on visiting the costume house in Rome.
Susan Shentall was a secretarial student when she was discovered by director Renato Castellani in a London pub. She proved quite an effective choice but Shentall wasn't interested in becoming a movie star. She married shortly after filming was completed and never returned to film-making.
Italian writer and playwright Ennio Flaiano played a cameo role in this movie as Prince of Verona, and is listed in the credits under his real name (Giovanni Rota).