- Dawson Casting: Boyarsky was 28 at the time the movie was filmed, while d'Artagnan is 18 in the book. This made for some Narm in a scene when d'Artagnan states his supposed age.
- Underage Casting: This applies to Madame de Chevreuse in the sequel. Olga Kabo was 22 when the production started - far too young to have a 15-year old son.
Trivia / d'Artagnan And Three Musketeers