When Vincent reads the newspaper clipping about Irene's father, the accompanying photograph of her father is that of director/screenwriter Delmer Daves.
The actual Art Deco apartment building used in the film (located at 1360 Montgomery St in San Francisco) is still standing as of December, 2008. The actual apartment is marked by a cardboard cut-out of Humphrey Bogart, which can be seen from the street. The site is visited frequently by fans of vintage film noir.
When Humphrey Bogart is riding in the car with Clifton Young during his escape, the voice on the radio is supplied by Dane Clark, another Warner's player.
There is an 8x10 photo shown in the film of Humphrey Bogart's character before his face surgery. The actor's face in the photo is of character actor Frank Wilcox.
Humphrey Bogart's complete uncovered face is not seen clearly until 62 minutes into the movie, when his character finally removes his bandages and looks into a mirror. All previous scenes with the character are either shown from his point of view or have his face obscured with shadows or bandages.