Continuity mistake: In the scene at the beginning of the movie where the flying vampires are chasing the security guard across the boardwalk parking lot, the positions of his arms as he is running changes back and forth between shots. In the close-ups of the guard's face, his hands are up, holding his hat down on his head. In the wide shots, his arms are down at his side. (00:02:45)
Continuity mistake: In the secret covenant, the amount of blood on Eve's white top decreases when Olivia the vampire doctor examines her wounds. This is most noticeable under the collar. (00:34:20)
Continuity mistake: When the group of girls first pulls up to the gas station and talk with Barney, the shadow cast by the sign is much longer than moments later when they leave. (00:11:15 - 00:12:50)
Continuity mistake: The last two pictures on the left on the wall going up the stairs change continually throughout the movie, at least 10 times. (00:24:35 - 00:26:35)
Revealing mistake: In the chase scene about an hour into the movie, Robert Loggia is shown entering the Liberty Tunnel, driving on a wet road. Note the vaulted round ceiling of the tunnel. Next, we see a series of shots of him in the tunnel, and then a shot of the sun rising over Pittsburgh as he is about to leave the tunnel. Here is the problem - the sunrise shot is taken from the Fort Pitt tunnel on a different day. Note the dry road, the barriers to the driver's left at the tunnel exit and the Fort Pitt bridge straight ahead. There is no place for the driver to make a left turn out of this tunnel. Also note that the POV is from the left lane. All the Liberty Tunnel shots show Loggia in the right lane. The next shot shows Loggia exiting the Liberty Tunnel and making a left turn from the right lane, causing a pile-up. (01:11:10 - 01:12:20)
Continuity mistake: Throughout the film Elvira wears her trademark black dress, split to the top of her thigh, and underneath it she always wears black pantyhose. Inexplicably, this changes to black stockings and suspenders when she is undressing for bed on her first night in her new house. (00:31:35)
Visible crew/equipment: After they've killed the snake, Alice says "Is it dead?" and as the camera pans up, the boom mic's shadow is visible moving across the wall, directly over Ned's head and the red box. (00:26:05)
Visible crew/equipment: After the gardening tools attack Roger in the shed, when Roger loads the shotgun to confront the marlin mounted on the wall, just as he enters the room and stops, the boom operator's raised arm is visible on the left side of the screen. (00:43:45)
Visible crew/equipment: When Mia first does the ritual, you can see the boom mic on the bottom right corner. It hides in the dark corner, but if you look carefully, you can see it come in the shot. It's easier to, depending on how dark your screen is. (00:20:40)
Continuity mistake: During the whack-a-robot game, a big chunk of the broken robot lies on the counter, but it disappears a shot later.
Continuity mistake: When Burt is hiding in the bulldozer scoop, Grady looks down at him from the top of the oil tank and we see that Burt has his knife in his hand. However, in the next shot, we see him pull the knife out of its sheath on his leg.
Visible crew/equipment: After Matthew and Elizabeth take the pills to stay awake, when they are found Matthew shouts, "David, don't let them touch her," and there's a visible T-mark taped to the floor in the overhead shot. (01:31:30)
Continuity mistake: When Dr. Loomis is thrown through the window by Michael Myers in the school notice that Myers' hair has strangely turned white. The next scene Myers' hair has gone back to being brown. This is more evident in the widescreen version. This is because during the hectic shoot, an unfinished mask that wasn't painted or dyed yet was accidentally grabbed by a crew member for that one shot. It wasn't caught until the film was being edited. (01:13:50)
Visible crew/equipment: When the martian space ships first appear you can see the wire suspending the models. You can clearly see the wires every time you see a martian or martian space ship.
Visible crew/equipment: When Charlie is in the ventilation system and says, "I could use some help here," the boom mike briefly pops into the picture. (00:44:40)
Visible crew/equipment: When Scott is finally killed by the giant scorpion, the hand of the puppeteer is seen on the left.
Continuity mistake: When Blade gets captured and stabbed in the room where the "Vampire Bible" is, he is not wearing an ear piece. In the next shot, he is. (00:51:45)
Continuity mistake: After Gen. Perez pushes the stacks of money towards Elgyn, they are right on the metallic edge of the table when the general offers a drink to Elgyn. In all of the following shots, the stacks have moved and are further in on the table, not on the metal anymore.
Continuity mistake: When Jason kills Lizabeth, the first shot shows Jason with his feet on either side of her head, but in the next shot, his feet are together and away from her head. (00:14:35)
Continuity mistake: When the tentacle monster rips out a chunk of Norm's chest, a large spray of blood splashes on his right-side jaw and cheek. In every subsequent shot of him, this blood is gone and his jaws are completely clean. (00:26:30)