Continuité: Visiting Wonderly, Spade finds that she has been reading a book. In close-up, its title is shown as "The Strange Case of the Little Black Bird", with a picture of the eponymous falcon on the jacket. But in other shots, it is "Famous Criminals and their Trials" (possibly the 1926 book by Sidney Theodore Felstead), with human portraits on the jacket.
Continuité: In the second-to-last scene, as Spade identifies killers to the police, his robe goes from being relatively neat to sloppy.
Révélant des erreurs: The same prop is used for the suitcase that Spade finds in Miss Wonderly's room and the suitcase which contains the falcon. The travel stickers are identical on each one.