Was approached to direct Clint Eastwood western Hang 'Em High (1968) , but he turned it down since he was working on Once Upon a Time in the West (1968) at the time.
Was often noted to embellish events that occurred on the sets of his films, as noted by many of his collaborators.
Was sued by Japanese director Akira Kurosawa for remaking his Yojimbo (1961) as "A Fistful of Dollars" (A Fistful of Dollars (1964)) shot-for-shot without crediting him, and copyright infringement. The production of A Fistful of Dollars (1964) apologized, compensated Kurosawa with $100,000, and 15% of box office revenues.
Was very insecure about the films he made and every film he made was almost his last. Between Duck, You Sucker (1971) and Once Upon a Time in America (1984) he produced several films and directed several commercials. He also did some uncredited directing work on some of the films he produced. Before his death he planned on making a film called The 900 Days about the siege on Leningrad. He was able to get $100 million in financing without even having written a script and he planned to cast Robert De Niro.
Was voted the 41st Greatest Director of all time by Entertainment Weekly, having directed only 11 films.
Was working on a screenplay idea called "A Place Only Mary Knows", which was to star Mickey Rourke and Richard Gere, which involved a Union soldier and a Southern conman searching for a buried treasure during the American Civil War.
When he made Once Upon a Time in the West (1968), his stylistic influence switched from the more frenetic pace of Hollywood westerns (which he put on hyper-drive for the "Dollars" trilogy with Clint Eastwood) to the slower, tenser style of Japanese samurai films, mainly those of Akira Kurosawa.
When his old friend Clint Eastwood - who was also close with Don Siegel - directed the Oscar-winning "anti-Western" Unforgiven (1992), Eastwood dedicated this film in memory of both Leone and Siegel.