There are only two close-ups in the movie: Joe firing his gun and Dude's hands trying to roll a cigarette.
The sets in Old Tucson are built to 7/8th scale, so the performers look larger than life.
Although Harry Carey Jr. was listed in the credits on-screen, he does not appear in the picture. Carey had a drinking problem at the time. He called director Howard Hawks "Howard" instead of "Mr. Hawks" on one of his first days on the set, infuriating Hawks. His contract, including his pay and his screen credit, was honored, but his part (a townsman) was cut.
The song "My Rifle, My Pony and Me" was originally used as the theme for Red River (1948), another John Wayne western. The original title was "Settle Down".
The movie had an interesting preview trailer. In the trailer, Ricky Nelson finishes playing his guitar, then he turns to the camera and talks about the exciting nature of the film. After some clips are shown, they cut back to Nelson who lists the cast members. When he does not mention his own name, we hear the voice of Dean Martin say off camera "What about Rick Nelson"?
For the first four full minutes of film (including credits) there is no dialog.
The movie was made by Howard Hawks and John Wayne as a counter-response to the underlying theme and point of view of High Noon (1952).
Ward Bond's death scene was filmed from a distance because it was actually a double. Bond had already left the set to be back on location for "Wagon Train" (1957).
After seeing the film, Gary Cooper said it was "so phony, nobody believes in it."
John Wayne was nervous about the love scenes between his character and Feathers, since he was 51 and Angie Dickinson was only 26.
On May 8th, just one week into shooting ‘Rio Bravo’, Ricky Nelson celebrated his 18th birthday. As a gift, John Wayne and Dean Martin gave him a 300 lb. sack of steer manure, which they then threw Nelson into as a rite of passage.
Shooting outside could be a chore as the temperatures in Arizona often reached as high as 120 degrees during the shoot.
Hawks' instructions to Martin who showed up in an almost comical cowboy outfit on the first day of shooting, were not to play a cowboy but just play a drunk.
Montgomery Clift turned down Dean Martin's role. John Wayne and Walter Brennan were outspokenly conservative and Clift's political views were diametrically opposed. This was a problem as early as the filming of Red River (1948) in 1946. During the filming of that picture they solved their differences by agreeing to not discuss politics.
This was Howard Hawks’ first film in four years. After the critical and box office failure of Land of the Pharaohs (1955), Hawks took a break from directing and lived in Europe.
Dean Martin's agent approached Howard Hawks to consider his client for the role of the drunken deputy Dude. Hawks agreed to meet with Martin at 9:30am the next morning. When Hawks learned that Martin had done a show in Las Vegas until midnight, and hired a plane to fly him to the meeting, Hawks was so impressed that he simply sent Martin to get a costume and told him he had the part.