Lee Marvin faked the recoil from the .44 Magnum when he shoots in Lynne's bed. These were in fact blanks, but afterward when shooting in Alcatraz they tried with real bullets and there was no recoil at all. Marvin said to director John Boorman, "Fiction overtakes reality". Marvin's revolver was a Smith & Wesson Model 19. It's a .38/.357 Magnum, not a .44 Magnum.

This movie and Payback (1999), with Mel Gibson, are both based on the book "Hunter" by Donald E. Westlake (as Richard Stark).

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The house where Walker (Lee Marvin) meets Brewster (Carroll O'Connor) was an actual house in the Hollywood Hills that was rented as a filming location. The Beatles once stayed in this house while visiting L.A. It was the basis for their song "Blue Jay Way", which is the name of the street on which the house sits.