In Texas, 1980, hitman Anton Chigurh strangles a deputy sheriff with the handcuffs he is wearing, escapes custody, and uses a captive bolt pistol to kill a driver and steal his car. He spares the life of a gas-station owner who guesses the result of a coin Chigurh flipped, revealing Chigurh’s adherence to his own personal “principles”.
Poaching pronghorns in the desert, Llewelyn Moss comes across the aftermath of a drug deal gone bad. He finds several dead men and dogs, a wounded Mexican man begging for water, and $2.4 million in a briefcase. He takes the money and returns home. That night, Moss returns to the scene with water. He is pursued by two men in a truck and escapes. At home, he sends his wife Carla Jean to stay with her mother, then drives to a motel in Del Rio, where he hides the case in his room’s air-conditioning duct.
Chigurh, hired to recover the money, arrives to search Moss’ home, where he uses his bolt pistol to blow the lock out of the door. Investigating the break-in, Terrell County Sheriff Ed Tom Bell observes the blown-out lock. Following an electronic tracking device hidden in the money, Chigurh goes to Moss’ motel room and kills a group of Mexicans who are waiting to ambush Moss. Moss has rented a second room adjacent to the Mexicans’ room with access to the duct where the money is hidden, unintentionally tricking Chigurh to dispatch the Mexicans. He retrieves the briefcase just before Chigurh opens the duct and finds it empty.
Moving to a hotel in the border town of Eagle Pass, Moss discovers the tracking device after feeling suspicious of why his pursuer could track him so easily, but Chigurh has already found him. Their firefight spills onto the streets, killing a civilian, and both men are wounded. Moss flees across to Mexico, stashing the case of money in weeds along the Rio Grande. Finding Moss severely injured, a passing norteño band takes him to a hospital. Carson Wells, another hired operative, fails to persuade Moss to accept protection in return for the money. Chigurh cleans and stitches his own wounds with stolen supplies and sneaks up on Wells at his hotel. After Wells unsuccessfully attempts to barter for his life, Chigurh kills him in his hotel room. Moss telephones the room and Chigurh answers; Chigurh vows to kill Carla Jean unless Moss gives up the money.
Moss retrieves the case from the bank of the Rio Grande and arranges to meet Carla Jean at a motel in El Paso, where he plans to give her the money and hide her from danger. Chigurh kills the man who hired Wells, then heads to El Paso, having figured out Moss’ plan. Carla Jean is approached by Sheriff Bell, who promises to protect Moss. Carla Jean’s mother unwittingly reveals Moss’ location to a group of Mexicans who had been tailing them. Bell reaches the motel rendezvous at El Paso, only to hear gunshots and spot a pickup truck speeding from the motel. Bell approaches Moss’ room and finds Moss lying dead. When Carla Jean arrives, she chokes up upon discovering her husband’s fate.
That night, Bell returns to the crime scene and finds the lock blown out. Chigurh hides behind the door after retrieving the money. Bell enters Moss’s room and sees that the vent has been removed. Later, Bell visits his uncle Ellis, an ex-lawman, and tells him he plans to retire because he feels “over-matched”. Ellis clarifies that the region has always been violent, and that it will continue to be violent.
Weeks later, Carla Jean returns from her mother’s funeral to find Chigurh waiting in her bedroom, as per his threat to Moss. She refuses his offer of a coin toss for her life, stating that the choice is entirely his own. Chigurh checks his boots for blood as he leaves the house. As he drives through the neighborhood, he gets severely injured in a car accident. He bribes two young witnesses for their silence and flees.
Now retired, Bell shares two dreams with his wife. He claims the first does not have much meaning; he lost some money his father had given him. In the other, he and his father were riding through a snowy mountain pass; his father had gone ahead to make a fire as Bell continued traveling alone in the darkness, knowing that his father will be waiting for him in the distance ahead.