Revealing mistake: During the big fight scene, just as Annie Wilkes falls to the floor and hits her head on the typewriter, the actress is replaced by a really bad looking Kathy Bates dummy!
Audio problem: In the scene where James Caan's character is lying in bed, practising grabbing a large knife from his arm sling, there is the metallic sound as he pulls out the knife. In the sling are his arm and the knife. There is nothing the knife could be pulled against to make the sound.
Continuity mistake: When Buster and his wife Virginia, first get in their 4x4 truck to head down the road, they discover that broken tree limb. Before he yells "stop!", the only part of the road not covered in snow is the tire tracks. After he walks back up the hill (and Annie drives by), the road has no snow on it.
Revealing mistake: When Paul goes through Annie's scrapbook, a fast reader may notice that several newspaper clippings (although having different headlines and being based on separate events), have the exact same story underneath. The text has simply been repeated, rather than a new report being created for each story.
Other mistake: When Annie returns after yelling at him for killing Misery, she finds Paul on the floor next to the bed wrapped in blankets. How did he wrap himself so tight?
Continuity mistake: When the sheriff looks at the last newspaper article about Annie, the caption reads "There is a higher justice than that of man..." Then when it zooms in on the caption it is switched to "There is a justice higher than that of man..." (The 2nd one matches the Misery book quote).
Continuity mistake: When Annie lifts Paul off the floor and lays him back into the bed, there is initially no tape over the brace on Paul's left knee. In the next shot, which is somewhat bird's eye view, there are three pieces of white tape over the brace, then there are none again when she finishes lying him down.
Visible crew/equipment: When Paul is in the kitchen, he looks at the knives. In the stove is the reflection of a person with a white shirt, but Paul is wearing a red shirt.
Continuity mistake: After Paul burns the manuscript on the grill, Annie begins to take it out of the room after pouring water on it. In the shot in the room, the grill is smoking, but in the shot from the doorway, the papers have suddenly stopped smoking and there is no smoke anywhere else in the room.