The legendary gunfight took place on October 26, 1881 and lasted thirty seconds, resulting in three dead men after an exchange of thirty-four bullets. The fictionalized gunfight in this movie took four days to film, and produced an on-screen bloodbath that lasted five minutes.
Jo Van Fleet, who had trained at Actor's Studio, needed help to get into the character of the abused woman. She asked Kirk Douglas to hit her in the face. So he did.
In his 1988 autobiography "The Ragman's Son", Kirk Douglas wrote that while playing Doc Holliday, he planned exactly how many and what kinds of coughs he would have in each scene so that continuity wouldn't be a problem once the film was edited together.
Kirk Douglas and Burt Lancaster had worked together in I Walk Alone (1947), and often saw each other at various Hollywood functions. But, as Douglas recounted in his autobiography, "The Ragman's Son", they didn't become friends until this movie, which lead to some pretty loose-and-easy moments on the set. For instance, they couldn't focus during a scene in which an unarmed Lancaster is surrounded by several men in a saloon, only to be rescued by Douglas, who steals another man's gun and tosses it to Lancaster. "We go out on the porch", Douglas wrote, "and Burt says to me, 'Thanks, Doc'. I was supposed to say, 'Forget it.' When I came to 'Forget it', the ridiculousness of the scene, our great bravery, our machismo, made us howl. We did the scene over and over. It just made us laugh harder." They were finally laughing so much, an angry John Sturges had to send them home for the day.
This film served as one of the inspirations for Mel Brooks' spoof Blazing Saddles (1974). The silliness of the lyrics of the theme song and the passion with which they were sung was the reason why Mel Brooks selected the same singer - Frankie Laine.