Production
Patrick Curtis, then married to Raquel Welch, met with Tony Tenser of Tigon British Film Productions with a view to obtaining funding for a movie starring Welch. Curtis proposed a horror movie or a Western; Tenser, who had always wanted to make a Western, picked that. Tigon put up 100% of the budget, while Curtwel (Curtis and Welch's production company) put up their services. Neither Curtis nor Welch took a salary, instead taking profit participation. Before Hannie Caulder was released, Tigon and Curtwel co-produced The Sorcerers (1967), a horror film starring Boris Karloff. Thus, Curtis and Tenser teamed up for both a Western and a horror film.
The screenplay was rewritten by Kennedy, who was not credited.
It was the third film from Curtwel, following A Swingin' Summer (1965) and The Beloved (1971).
Robert Culp was signed to co-star in December 1970.
The movie was filmed in Spain, mostly around Almería, beginning on January 18, 1971.
Filming started January 1971. Kennedy wrote in his journal " David Haft is the producer of Hannie Caulder. He thinks he’s a writer—what he says goes. I hope he doesn’t say Raquel Welch, because without her, we have no film. Pat Curtis, Raquel’s husband, says he’s the boss, and what he says goes. Wish to hell he’d say David Haft."
Burt Kennedy and the cast were reportedly not paid after the first two weeks of filming, causing tension on the set. Filming resumed.
In June 1971 Kennedy said the producers "cut Hannie Caulder into a mess." He claims he recut it and the film was sold to Paramount within half an hour.