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.
Other 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.
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.
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: When Annie Wilkes returns with the typewriter for Paul, she says that the letter 'N' is missing. However, the button is there during the writing montage.
Continuity mistake: When Paul hops out of bed after Annie yells at him for killing Misery, you can see his legs move in the braces several times, even though they should be immobile.
Continuity mistake: In the scene where Kathy Bates shoots the sheriff at the top of the stairs, his body collapses and falls on the steps. However, in the next shot, the body disappears.