Anton Chigurh kills or tries to kill almost every person he speaks to during the film. The only people he spares are the gas station proprietor, the woman who works in the trailer park office, the woman at the motel front desk, and the two children at the end. It is unclear if he kills the man who is in the office when he executes the Businessman. He is unable to kill Moss, who instead is killed by the Mexicans. It is implied that he kills Carla Jean when he checks the soles of his boots - presumably for blood - after he exits her house.
In the novel, Sheriff Bell says of the dope-dealers, "Here a while back in San Antonio they shot and killed a federal judge." Cormac McCarthy set the story in 1980. In 1979, Federal Judge John Howland Wood was shot and killed in San Antonio by Texas free-lance contract killer Charles Harrelson, father of actor Woody Harrelson (Carson Wells).
When Joel Coen and Ethan Coen approached Javier Bardem about playing Chigurh, he said "I don't drive, I speak bad English, and I hate violence." The Coens responded, "That's why we called you." Bardem said he took the role because his dream was to be in a Coen Brothers film.
Josh Brolin broke his shoulder in a motorcycle accident two days after winning the part in this film. In an interview with NOW magazine, he reported thinking as he flew over the car that hit him, "Fucking shit! I really wanted to work with the Coens." His injury turned out to be non-issue since his character is shot in the shoulder very early in the film.
While on location in Marfa, Texas, There Will Be Blood (2007) was shooting nearby. One day, while filming a wide shot of the landscape, directors Joel Coen and Ethan Coen had to halt shooting for the day when a gigantic cloud of dark smoke floated conspicuously into view. Paul Thomas Anderson was testing the pyrotechnics of an oil derrick set ablaze on the set of his film. The Coens resumed filming the next day, when the smoke finally dissipated. A year and a half later, both films were the leading contenders at the Academy Awards.
Josh Brolin was making Grindhouse (2007) when he was turned on to role of Moss. He asked the film's director Robert Rodriguez if he could borrow a video camera for his audition tape, and he ended up having his audition elaborately shot with the theatrical camera they were using, directed by Quentin Tarantino, and with Marley Shelton as Carla Jean. When the Coens saw Brolin's tape, their response was that they loved the lighting.
Joel Coen and Ethan Coen used a photo of a brothel patron taken in 1979 as a model for Anton Chigurh's hair style. When he first saw his new haircut, Javier Bardem said "Oh no, now I won't get laid for the next two months". The Coens responded by happily high-fiving; Bardem's response meant Chigurh would look as creepy as they'd hoped.
Contrary to most successful films made from books, much of the film's action is taken word for word from Cormac McCarthy's novel, and occurs in the same order. For instance, Bell's final speech in the film is on the final page of the book. However, unusually for Joel Coen and Ethan Coen (usually known for their extremely loquacious characters), they decreased the amount of dialogue found in the book, substantially in some scenes.
Llewelyn tries to buy a kid's Templeton Eagles jacket. Josh Brolin was raised in Templeton, and asked the production if the jacket could be from his high school. "So we called the school and they gave us a Templeton Eagles windbreaker, and that was really moving for me when I watched the movie to see me put on the windbreaker and see Templeton Eagles just plain as day on this 60-foot screen. [That] was just great."
The credited editor for this film, Roderick Jaynes, is a pseudonym for Joel Coen and Ethan Coen, who have co-edited, co-directed, and co-written all of their movies since Blood Simple. (1984) New York magazine reported that they devised the pseudonym when Guild membership rules would not allow two co-credited editors on the same film. Jaynes was nominated for an Oscar for editing Fargo (1996) and "No Country for Old Men", but he has never won one. Joel Coen told New York magazine that if Jaynes had won the Oscar, the Academy would have allowed the award presenter to accept the award on "his" behalf.
Carson Wells mentions to Stephen Root's character that one floor in a building seems to be missing. This may refer to the fact that most buildings do not have a thirteenth floor, which many considered an unlucky number. Building owners often rename the floor 14, or give the floor some other use and rename it a letter. The novel implies that the floor in question - the 17th - isn't listed in the building's directory for security purposes, and is thus "missing".
Score music is used quite sparsely throughout the film, blending elusively into the background. Some can be heard during Bell's opening narration, during Chigurh's quarter speech, when Bell shows up at the aftermath of the motel shootout towards the end of the film, and the closing credits.
An unforeseen expense for the film was the make-up department buying in expensive fake blood at $800 a gallon. Joel Coen realized why they were spending so much when it came to film the scene where Llewelyn stumbles across the aftermath of a shootout with lots of extras lying around dead in the dust. Ordinary fake blood (made with sugar) would have meant the extras would have been crawling with bugs and ants, while the insects had no interest in the expensive stuff.
After he blows up the car, Chigurh enters the Mike Zoss Pharmacy. It's a reference to Mike Zoss Drugs, a Minneapolis pharmacy where the Coen Brothers spent time in their youth. The Coen Brothers also named their production company Mike Zoss Productions.
When Llewelyn Moss (Josh Brolin) crosses the border into Mexico, he becomes the first character in a Coen Brothers movie to set foot outside of the United States. Except for their contribution to the anthology film Paris, je t'aime (2006), no other film written/directed by the Coens takes place in a foreign country.
Contrary to their usual process, Joel Coen and Ethan Coen did not write the script with actors in mind for the characters. Stephen Root ended up being the only actor in the cast with whom the Coens have previously worked.
Joel Coen and Ethan Coen share the record of four Oscar nominations for a single person for the same film (in this case, shared by the two) with Orson Welles' four nominations for Citizen Kane (1941) and Warren Beatty's for Reds (1981). The Coens' four nominations are for Best Picture (as producers with Scott Rudin), Best Director, Best Adapted Screenplay, and Best Editing (under the pseudonym Roderick Jaynes). Welles was nominated both Best Picture (also as producer) and Best Director, as well as Best Original Screenplay (won, and shared with Herman J. Mankiewicz), and Best Actor. On the other hand, Beatty was nominated for Best Picture (also as producer), Best Director (won), Best Original Screenplay with Trevor Griffiths and Best Actor.
There is a strong visual clue (not in the book) that Chigurh did kill Carla Jean. Chigurh apparently does not like to get blood on himself; after he kills the Mexicans in the motel, he takes off his socks which presumably have blood on them, and after killing Wells, he lifts his feet off the floor. As he exits Carla Jean's mother's house, he pauses to check the soles of his boots.
When Moss is lying hurt on the floor, after crossing the Mexican border, a mariachi group starts singing to him. What they say, in English, is: "You wanted to fly without wings, you wanted to touch the sky, you wanted too much wealth, you wanted to play with fire", probably in a reference to the story of the film.
While what is seen in the movie is virtually verbatim from the book, there were many scenes in the book that were cut from the script/movie. Some of the more major of these scenes include: Chigurh staying at the motel for five days after being shot, and leaving when Sheriffs arrive at the place; Mexicans arriving during the scene where Chigurh and Moss face off in the streets, all of whom Chigurh kills; Sheriff Bell finding an old woman in an apartment killed from a stray bullet from the showdown between Chigurh, Moss, and the Mexicans; Sheriff Bell finding the owner of the motel where Chigurh found Moss dead with a hole in his head from Chigurh's cattle gun; an entire subplot where Moss picks up a hitchhiker on his way to el Paso, after he retrieves the money, whom he befriends and gets to know before he is killed by the Mexicans; Chigurh entering the motel room Moss was killed in to retrieve the stolen money; Chigurh returning the stolen money to its original owner and beginning a working relationship with the owner; Chigurh sneaking into Carla Jean's grandmother's house when they are not there and sleeping there overnight; Sheriff Bell interrogating one of the boys who made contact with Chigurh after Chigurh's car accident; and, the rest of the encounter with Carla Jean and Chigurh, where Carla Jean incorrectly guesses the side of Chigurh's coin, and is shot by Chigurh after he explains to her why his killing her is out of his control. The book also explains (by Chigurh himself, during a conversation) why Chigurh was arrested at the very beginning of the book (also in the first scene in the movie). The only scenes added to the movie were the scene with the Mariachi band and the last half of the scene where Chigurh kills the man who hired Wells (When he first encounters the accountant until "That depends...do you see me?"). The scene where Moss talks to a woman by a swimming pool was not in the book, but was an alternate scene rather than an added scene; it takes the place of a scene in the book where Moss talks to the girl who hitchhikes with him on the road to el Paso. Two other important alternate scenes were Bell finding and identifying Moss's body in a Morgue, rather than the crime scene as in the movie; and Bell traveling to Carla Jean's grandmother's house to tell her of Moss's death there, rather than encountering her at the crime scene. Also, even though virtually all of the dialogue in the movie is verbatim from the book, many (if not all) of the conversations between characters in the book were heavily condensed for the movie.