Continuity mistake: When Rick Nelson tells Angie Dickinson to throw the plant pot through the window to distract the gunmen who threaten John Wayne he seems to have had a hair cut between scenes as his sideburns are halved by the time he reaches the street and grow again later.
Continuity mistake: When the sheriff goes to the hotel bar and talks to "Feathers", she picks up a bowl and then the camera angle changes and the bowl is back in the corner. Also, the shot glasses they use keep changing positions. They're a few inches apart then a foot apart, then close again.
Continuity mistake: In the film's climax, Ricky Nelson is shooting out a window. A bullet hits on the frame and gouges the wood. In the next camera shot of Ricky the gouge is gone and the following shot, it is back.
Audio problem: When the sheriff offers Dude a beer and says, "It's cold," when Dude is getting off his horse he says, "As long as it's beer," but his lips don't match the words.
Revealing mistake: The bullet hole gouge in the window frame near Ricky Nelson and the outward facing splinters at the bullet hole in the door frame near John Wayne indicate exit holes.
Continuity mistake: The sheriff, Carlos and wife and Feathers are in the back room. The sheriff asks Feathers if she was sorry she missed the stage. When he does, Carlos' wife turns her head to look at Feathers then turns back to the right. Immediately after she does that, the scene switches angles and she is shown turning her head to the right again.
Continuity mistake: After Colorado tells the sheriff what the music is about, the sheriff goes into the jail and sits on the desk. He sits on the brim of his hat on the desk. In the next shot his hat has moved away and in on the inkwell.
Continuity mistake: When Dude is getting a shave from "Feathers", she does under his nose, but when she says she's done and he goes to stand up there is a white strip under his nose. After the towel's off it's gone.
Plot hole: Dude, the deputy, is on the road at the end of town to take the guns away from those that enter town. This was pointless. Nobody is watching the other end of town. When Nathan and his men came to town, all they had to do to avoid Dude was ride in the desert and they could have entered the town anywhere they wanted.
Other mistake: When Joe shots the person at the beginning of the movie the character is played by Bing Russell (Kurt's father). Later in the movie when Dude is ambushed at the entrance to the town, they give a guy his hat to impersonate Dude - it's Bing Russell again, after he was killed off at the beginning and why Joe is arrested in the first place.
Continuity mistake: The brim of John Wayne's battered hat goes through so many changes I stopped counting - in one sequence it's bent upward, in the next it is flat, in the next it's bent up (even more) again, etc.
Continuity mistake: When Dude is in the bar looking for the man that ran in there, there is a mug of beer on the bar. It is right up against the rail. Later, it's in the middle of the bar then against the rail again.
Continuity mistake: When Burdette rides into town the camera is behind Dude and he has his hands on his belt. The camera angle changes to his front and he suddenly has his left hand on the hitching post.
Continuity mistake: When the sheriff is talking to Wheeler at the bar, they move to a table and the sheriff pulls down the shade. As they talk the camera angle changes and so does the bottom of the shade. Now you see the window sill.
Continuity mistake: When Dude is in the bar looking for the man that ran in there, they show a view from the man up in the loft. Look at the pool table in the background. It has balls and cues on it which change positions as that bar scene plays out.
Other mistake: When Wheeler is walking down the street, the view is from behind a man with a rifle at a window. When he shoots it is obvious the rifle was pointing to the far right of Wheeler.