This imaginative female writer established herself as a novelist, writing in genres from fantasy to detective fiction to Westerns before segueing to creating mostly male-oriented films. Leigh Brackett often collaborated with Howard Hawks, notably on the superb film noir "The Big Sleep" (1946) and the cycle of excellent Westerns that began with "Rio Bravo" (1958) and ended with "Rio Lobo" (1970). Although her first released film was "The Vampire's Ghost" (1945), for which she provided the story and screenplay, Brackett received her first real notice for "The Big Sleep", adapted from Raymond Chandler's novel. The screenplay, credited to Brackett, William Faulkner and Jules Furthman, was a bit convoluted, but Hawks' superlative direction and the performances of leads Humphrey Bogart, Lauren Bacall and Martha Vickers helped to create a classic. (The film was originally shot in 1944, but held for release until 1946. The final version released had been trimmed somewhat; in 1997, the pre-release version was shown in NYC and while the story remained somewhat vague, some plot points were clarified by the additional footage.)

The script writer received solo credit for William Castle's "Crime Doctor's Man Hunt" (1946), one of the snappier entries in the series featuring Warner Baxter. After a twelve-year absence from screenwriting, Brackett returned to work for Hawks with "Rio Bravo", co-written with Jules Furthman and starring John Wayne. She also worked on the scripts for several subsequent teamings of Wayne and Hawks: the Africa-set adventure "Hatari!" (1962); "El Dorado" (1967), a follow-up to "Rio Bravo" that also starred Robert Mitchum and James Caan; and Hawks' final film, "Rio Lobo", which saw Wayne as a former army officer out to settle some scores. In 1973, Brackett turned another Chandler novel, "The Long Goodbye", into a bit of a spoof of film noir for director Robert Altman.

Before her death in 1978, Brackett handed in the first draft of "The Empire Strikes Back" (1980), the sequel to George Lucas' "Star Wars" (1977) which was essentially a Western in outer space. The final script, co-credited to Brackett and Lawrence Kasdan, amalgamated several of the genres in which she had made her mark (i.e., fantasies and Westerns). While Brackett was not the only female writer of oaters and detective thriller, she was perhaps the most famous, working on the most prestigious projects. Several of her many novels were also turned into movies, notably, "The Tiger Among Us" which Philip Leacock filmed as "13 West Street" (1962), with Alan Ladd as an army veteran who takes justice on a gang of street thugs, and her "Eye for an Eye" became the 1958 NBC TV pilot "Markham", starring Ray Milland.