Factual error: The idea that anyone survived living in Pripyat Hospital is absurd. The uniforms of the doomed firefighters were stored in the basement and are so radioactive that anyone straying downstairs for more than 45 seconds has about a week to live. The ground and upper floors are far less radioactive but prolonged exposure - in other words, living there - would be fatal. Nobody could survive on the grounds for more than two or three months without receiving a lethal dose of radioactivity. Incidentally, prolonged exposure to radioactivity doesn't turn you into a deranged zombie - it turns you into a corpse.
Continuity mistake: When the car door is ripped off by the cow, it shows the truck with the door intact.
Continuity mistake: When Chris talks to the cop and then the cop gets shot with an arrow, Chris runs into the truck and the man shoots another arrow. So altogether he shoots two times. The first one is in the cop's eye, so how come when he shoots the second through the truck window, there are now two arrows there, not one. He only fired two arrows and we see three. (01:04:20)
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.
Other mistake: After Michael kills Laurie at the beginning, he hands the knife to the inmate with the clown mask. The next kill is the cameraman for which he uses the tripod ends. A few scenes later they show Michael standing holding a knife with fresh blood on it. He hasn't killed anybody with this knife yet so where did the blood come from?
Visible crew/equipment: At the start of the film, just after the war exercise, when the Sergeant begins yelling at the recruits you can see the outline of his microphone under his T-Shirt. (It's not his dog tags because you can see the shape and dog tags are not shaped like that.)
Deliberate mistake: When the ship crashes into the dock, all of the scenes leading up to the crash and after it show a clear view across the harbor as we can see lights and land on the other side. It's not until the ship is about to crash that a thick and dense fog appears and disappears within a minute to mask the ship to create a more dramatic effect.
Continuity mistake: In the scene where Jonathan picks up the scarab, it breaks open and the beetle inside starts to crawl under his skin. We see Brendan Fraser tear Jonathan's shirt and cut the beetle out of him. However, in the very next scene, we see Jonathan walking into the temple, his shirt is intact and there is no blood to be seen. (01:37:05 - 01:38:30)
Visible crew/equipment: When Ashley is running down the corridors before escaping back into her medical room, you can see the dolly that The Engineer chasing her is being pushed on. (01:04:50)
Other mistake: During his conversation with the landlord of the pub he ends up staying in, Sergeant Howie makes it clear that he did not intend to stay on Summerisle overnight, that he had been delayed and so needed accommodation. Makes you wonder why he packed his pyjamas. He's wearing them when Britt Ecklund does her famous naked song and dance routine, and they are not new so we know he didn't buy them that day. When he arrived he didn't even think he'd be on Summerisle for more than a few hours - we don't see him with so much as an overnight bag.
Revealing mistake: When Eric Matthews is smashing his foot, he hits it the first time and it shows a close up. If you watch the small amount of blood when he hits it again they have used the same shot. (00:04:00)
Continuity mistake: When Mommie is cutting Christina's hair it keeps on changing from long to short several times.
Continuity mistake: When John is driving to work and he hears Anna on the radio, he swerves to avoid a car. From inside the car you can see that there are no cars in the rear window, yet when the shot changes to an outside shot, there are 3 cars. (00:33:35)