Kim Basinger was originally cast as Catherine Tramell.
Two other actresses who turned down the role of "Catherine" were Michelle Pfeiffer and Greta Scacchi.
Michael Douglas' character watches Hellraiser (1987).
The dresses that Sharon Stone wears throughout the film were designed to match, in the same order, the dresses that Kim Novak wears in Alfred Hitchcock's Vertigo.
Michael Douglas' character in this film is named Nick. He also played characters named Nick in both Black Rain (1989) and The Game (1997) (which, like Basic Instinct, is set in San Francisco -- the setting for Douglas' breakthrough role on "The Streets of San Francisco").
Michael Douglas (a former race-car driver) did most of his own stunt driving in the film.
Both the story and specific shots are similar to Alfred Hitchcock's Vertigo (1958): A beleaguered San Francisco detective with a guilty conscience follows around and falls in love with a mysterious blonde woman who has an eerie double (Sharon Stone was dressed and styled to resemble Kim Novak as well). The shot of Nick walking down the stairs outside his apartment is a match for Hitchcock's tower shot in Vertigo, and the stabbing scene of Gus on the elevator is a copy of Psycho (1960).
Source: IMDb.com