The role of Llewelyn Moss was originally offered to Heath Ledger, who turned it down to spend time with his newborn daughter Matilda.

Garret Dillahunt auditioned five times for the role of Llewelyn Moss but was instead offered the smaller part of Deputy Wendell.

Josh Brolin, who was not the Coens' first choice, enlisted the help of Quentin Tarantino and Robert Rodriguez to make an audition reel during the production of Grindhouse, which eventually secured him a meeting with the Coens.

Javier Bardem nearly withdrew from the role of Anton Chigurh due to scheduling conflicts, and English actor Mark Strong was put on standby to replace him before the issues were resolved.

Producer Scott Rudin bought the film rights to Cormac McCarthy's novel and suggested the adaptation to the Coen brothers while they were attempting to adapt another novel, To the White Sea by James Dickey.

This was the Coen brothers' first straightforward literary adaptation, unlike earlier films such as Miller's Crossing (loosely based on Hammett) or O Brother, Where Art Thou? (inspired by the Odyssey).

The Coen brothers had never met Cormac McCarthy while writing the script and only met him during filming; Ethan Coen said McCarthy chuckled a few times while watching the finished film, which he took as a sign of approval.

Filming took place in New Mexico (Santa Fe, Albuquerque, Las Vegas) and West Texas (Sanderson, Marfa), with Las Vegas, New Mexico doubling for the border towns of Eagle Pass and Del Rio, Texas.

The Coen brothers had to scrap an entire day of filming because smoke from the oil derrick scene being shot nearby for Paul Thomas Anderson's There Will Be Blood, also filming in Marfa at the same time, ruined their shots.

The U.S.-Mexico border crossing bridge shown in the film was actually a freeway overpass set built in Las Vegas, New Mexico, at an intersection where the two depicted roads do not actually meet.

Cinematographer Roger Deakins, working on his ninth collaboration with the Coens, shot the film with meticulous planning, using only about 250,000 feet of film compared to the 700,000 to a million feet typical of similarly sized productions, and never used a zoom lens.

The film contains only about 16 minutes of music, much of it during the end credits, as the Coens deliberately minimized the score to remove the traditional 'safety net' of music guiding audience suspense.

Composer Carter Burwell used Buddhist singing bowls instead of traditional instruments, and tuned a swelling ambient hum during the coin-toss scene to the 60-hertz frequency of a refrigerator.

The distinctive foley sound for Anton Chigurh's captive bolt pistol was created using a pneumatic nail gun.

No Country for Old Men is the most recent Western to win the Academy Award for Best Picture, following Cimarron (1931), Dances with Wolves (1990), and Unforgiven (1992).

A 2014 study by researchers at the Université libre de Bruxelles found that Anton Chigurh is considered the most clinically accurate portrayal of a psychopath in film to date.

In 2024, the film was selected for preservation in the U.S. National Film Registry by the Library of Congress for being culturally, historically, or aesthetically significant.