Revealing mistake: When Carl is being dragged away by the demons, you can see the cable line that he's attached to. May be fixed on DVD.
Plot hole: At the end of the film, we see Edward carving ice sculptures in his mansion. How did he get the ice up there? First of all, it takes place in a warm climate and I didn't see a freezer up there in the castle. He couldn't have gotten ice from town because firstly he had scissors for hands and couldn't have gripped the ice. And, even if by some miracle he could, he wouldn't be able to buy any from town because everyone in town but Kim was convinced that Edward was dead, she told everyone that they killed each other. And Kim didn't bring it to him because she told her granddaughter in the end that she never saw him again after that night. So where did he get that ice?
Revealing mistake: In the library scene when Richie sees Pennywise the clown, all the balloons filled with blood are popping on people who aren't supposed to be able to see them, but one lands on a lady and you can see her jump as the balloon pops.
Factual error: When the Security Guard in the pump room gets bitten on the nose, he starts shooting with his revolver (a SIX shooter). Count the bangs. He manages to fire SEVEN times. (00:39:45)
Continuity mistake: Near the end of the movie, when Snow White has already been tied up by Lord Malice, the Dwarfelles come to rescue her. As the Dwarfelles are beating up Lord Malice, there's a quick shot of Snow White again and she is untied and has her hands covering her cheeks. Next shot, the fighting between the Dwarfelles and Lord Malice continues and Snow White is again tied up.
Continuity mistake: Toward the end, when James Belushi swerves to miss his dog in the middle of the street he crashes his car into a parked car and then roll to a stop. Notice before the camera cuts to a frontal shot of the wrecked car, that there is a huge spider crack in the windshield, as if James hit it with his head. This huge spider crack then disappears once the camera cuts to the frontal shot and the windshield is in perfect shape. (01:33:45)
Continuity mistake: When the white cop pulls out all of his healthy lunch on the desk he lines them up. And the camera pans across everything that he has. But when they pan out the items are not lined up the same.
Continuity mistake: After Cody leaves prison and gets in the car with his friends, we see him letting Angel into the back seat, then just two seconds later, when the camera switches to the view of the prison, we can hear the engine started. He couldn't wait for Angel to enter, then enter himself and start the car in two seconds.
Continuity mistake: During the final battle between Boone and Decker, at one point, they are wrestling on a wooden bridge, and the board beneath Boone's head breaks in half and falls into the cavern below. (It is even highlighted in a very dramatic shot looking downwards over the whole cavern as it falls) Yet, a few shots later, the board has suddenly re-appeared beneath his head, unbroken.
Factual error: When Bill Cosby (as a ghost) goes to the doctor and the doctor checks his heart (which is not beating), Bill Cosby then presses play on a tape recording of a sound of a beating heart. The doctor hears this through the stethoscope, even though the tape recorder is behind Bill's back, which is not possible.