Other reviewers have noted the fine cast in "Casanova's Big Night." Bob Hope was an excellent stand-up comedian, but his shtick in movies begins to wear thin rather fast. Part of it may be a lack of freshness among his writers, and part may be his performances. This film has an interesting premise, and some good comedy "action" scenes. Two things that boost it a notch or two above most of his films are the excellent costumes and sets in this film; and Hope's performance as a foreign baroness, especially his hilarious dance scene with the main villain, The Doge.
The supporting cast are all quite good, and some big names in Hollywood of that time. Joan Fontaine, Basil Rathbone, Vincent Price, John Carradine, Raymond Burr and others. After I watched the film recently and saw Lon Chaney Jr. in the credits, I had to go back and watch his part again. The makeup was so good I still couldn't identify him clearly in Emo the Murderer.