In the gun store, everything Eli Wallach does with the guns is completely unscripted. Eli knew little about the guns, so he was instructed to do whatever he wanted.
Because Sergio Leone spoke barely any English and Eli Wallach spoke barely any Italian, the two communicated in French.
Eli Wallach would have been decapitated during the train scene if he had lifted his head up. In the wide-shot, you can see the step that would have impacted his head.
Clint Eastwood wore the same poncho through all three “Man with No Name” movies without replacement or cleaning.
Sad Hill Cemetery was a very-convincing set piece constructed by the pyrotechnic crew and not a real cemetery. Today the site is marked as a local point of interest. Though the central stone ‘proscenium’ and parapet are gone, the circles of grave-mounds are still quite prominent.
Ennio Morricone’s iconic theme music was designed in places to mimic the sound of crying hyena.
Although Clint Eastwood is usually top-billed in this film’s credits, Eli Wallach has the most screen-time.
The film was budgeted at an expensive (for the time) $1.6 million.
Orson Welles warned Sergio Leone not to make this movie on the grounds that Civil War pictures were box office poison.
Sergio Leone originally titled his story “The Magnificent Rogues” and “The Two Magnificent Tramps,” but impulsively changed it during a meeting in which he was pitching the story to United Artists executives Arnold Picker and Arthur Krim. The improvised new title amused them both, and they agreed to put between $1.2 and $1.6 million to make it and retain North American distribution rights.
Charles Bronson was offered both the roles of Tuco and Angel Eyes (the latter because Sergio Leone feared that audiences would not take kindly to Lee Van Cleef going from the fatherly, likable Col. Mortimer to a sneering villain. He declined both.