The character, however, is widely cited as a crystallizing figure in the development of hard-boiled private detective fiction—Raymond Chandler's Philip Marlowe, for instance, was strongly influenced by Spade.

Spade combined several features of previous detectives, most notably his detached demeanor, keen eye for detail, and unflinching determination to achieve his own justice.

For your private detective does not—or did not ten years ago when he was my colleague—want to be an erudite solver of riddles in the Sherlock Holmes manner; he wants to be a hard and shifty fellow, able to take care of himself in any situation, able to get the best of anybody he comes in contact with, whether criminal, innocent by-stander or client.

[5] Though Bogart's slight frame, dark features and no-nonsense depiction contrasted with Hammett's vision of Spade (blond, well-built and mischievous), his sardonic portrayal was well-received, and is generally regarded as an influence on both film noir and the genre's archetypal private detective.

BBC Radio 4 adapted The Maltese Falcon in 1984, with Tom Wilkinson as Spade, while a 2009 dramatisation for the Hollywood Theater of the Ear starred Michael Madsen.