The flophouse location for this film was the Gladden Apartments in the Bunker Hill section of Los Angeles. Raymond Chandler, who wrote the novel on which this is based, lived in the building 30 years before the film was shot.
Screen rights were purchased from author Raymond Chandler for $2000 in 1942.
The Brasher Doubloon is a re-make of a Michael Shayne movie from five years earlier, Time to Kill (1942), with Heather Angel and Lloyd Nolan. Both movies were adaptations of Raymond Chandler's novel, The High Window.
The Brasher Doubloon broke several rules of the Hays Code - when Merle (Nancy Guild) was in Marlowe's apartment with a gun pointed at him, she told him to take off all his clothes; after he dominated the situation, he gave her a kiss that lasted more than 10 seconds. Later, she says that her boss grabbed her, and was going to tell that she was raped, and he changed the subject. Finally, she wanted to sleep in his apartment (knowing that they would have sexual relationship) against the Code, and he said that he was going to sleep in his office.
The value of the Brasher doubloon, set at $10,000 at the time of this 1947 movie, would be $138,000 in 2023. But actually, a Brasher doubloon was sold at auction in 2021 for $9.36 million, the second highest price ever paid for a U.S. gold coin.