Plot hole: After Blondie has "teamed up" with Angel Eyes, he hears a gunshot and says something like "Every gun sings its own tune", indicating that he's recognized the shot as being from Tuco's gun. But how did Tuco get his gun back? It certainly would have been confiscated when he entered the prison camp, and the chance that the guard on the train has that exact gun is extremely unlikely - he would most likely have had an officially issued sidearm.

Visible crew/equipment: When Tuco makes Blondie march through the desert, there is a shot at the very beginning and Blondie looks over his shoulder, feeling the strain of the desert. Then the camera focuses on Tuco and in this shot, you can see the tracks in front of his horse from a previous take.

Continuity: When Blondie is saved by the mortar shell, and it shows the empty noose, it is completely different than the noose that Blondie had around his neck. The loop that the noose went through to hold it to the beam has changed.

Revealing: When Tuco kills the fat man he is chained to whilst in the desert, in many shots this supposedly dead man can be seen breathing. Especially noticeable when he is on the tracks.

Factual error: Just before Angel Eyes confronts the girl in her room about the whereabouts of Bill Carson, we see her walking in the hall outside her room, and lighting this hallway is a very modern day lightbulb.

Visible crew/equipment: When Angel Eyes sits down at the dinner table in his first scene, there is a small unlit lantern hanging on the wall near his head, and unexplainable light sources reflected on it.

Visible crew/equipment: When Angel Eyes has finished paying the legless man for information, the legless man hops into the saloon. Notice he has two shadows, revealing the presence of stage lighting.

Revealing: When Blondie is to be hanged by Tuco, and saved by a extremely lucky hit by a Union mortar, you can see that the wall that will be hit by the grenade has been has been blow to pieces at least once before; the bricks have no mortar between them, and there is a large circular scorched area on the brick wall.

Continuity: Towards the beginning of the movie, Angel Eyes rides up to a house where he has to get information from a man inside and then kill him. After Angel Eyes kills him at the kitchen table, his son runs down some steps behind Angel Eyes in the background with a rifle in his hands. Angel Eyes pulls out his revolver, turns around quickly, and shoots him dead. Take note that the pistol is not pointing directly at the boy as he is firing it.

Revealing: During the scene where Blondie and Tuco are wiring the bridge with explosives, Tuco suggests they tell each other their part of the secret. As Blondie is replying, you can see a car drive by in the background. The movie takes place in the 1860s.

Factual error: When Tuco is in the gunshop messing around with the guns, one gun has the cylinder and barrel moving back and forth by manipulating the trigger guard-lever. This is a Belgian Galand & Somerville revolver, a gun that did not exist until 1868. This film takes place during the US Civil War, which ended in 1865.

Continuity: When Blondie abandons Tuco in the desert, watch the rope around Tuco's neck. It changes between shots, sometimes over his left shoulder, and sometimes hanging down in front of him. It is not due to the camera angle.

Continuity: When Tuco is riding his horse, he encounters three bounty hunters - one fires a shot making the horse misstep, and fall, bringing Tuco down to the ground. One of the bounty hunters ask Tuco, "Hey amigo, you know that you have a face beautiful enough to be worth $2,000.00?" He has a big blade of grass between his lips as he backs away from Blondie (Eastwood), however, there was no blade of grass between his lips when Blondie and he were close to one another. As he backed away, he had a rifle in his right hand and a wanted poster in his left, and he knew that Blondie had a gun pointed at him through his overcoat, so he was not able to put a blade of grass between his lips at any point.