The gunfight in the saloon is based on an actual gunfight that took place in the Lady Gay Saloon in Sweetwater, Texas on January 24th, 1876. The shootout involved Bat Masterson, a soldier known as Sergeant Melvin A. King (who was in reality a Corporal) and a woman named Mollie Brennan. King's character in this movie was Sgt. Ernie King, played by Charles Horvath and Mollie Brennan's character was Mollie Day, played by Kasey Rogers.
McCrea had intended for this to be his last film before retiring, and he remarked, "I've never been in a film that lost money."
Bat Masterson was 24 when this occurred. He is portrayed by 54-year-old Joel McCrae.
The opening gunfight takes place in a different (and real) Kansas town, Hays City. The climactic gunfight takes place in Dodge City and is strikingly similar to the opening in Gunsmoke (1955).
Originally entitled "The Bat Masterson Story", Mirisch re-titled the film "The Gunfight at Dodge City" to emulate the success of "Gunfight at the O.K. Corral" (1957).