* Errors in geography: The film is set in America but was shot in Ontario. During a shot of a dinner table, you can see the French logo for Kentucky Fried Chicken, PFK (Poulet Frit a la Kentucky). By law, Canadian products contain descriptions and company names in both English and French. The French side is visible.
* Crew or equipment visible: When Ana is driving through the suburban streets and passes a burning car, on the left side you can see that the adjacent street has not been wetted down to match the rest of the streets. Also, crew members and neighborhood spectators can be seen standing on the non-wet street and looking at the action being filmed.
* Continuity: When Ana is in the bathroom in the beginning, trying to get away, the lock on the window is in the down, locked, position. In the next shot that shows the window it's in the up, open, position. In the next shot she flips the lock up to open the window and opens it.
* Errors in geography: Film is set in Milwaukee Wisconsin but the license tag on the ambulance at the beginning reads Ontario (the actual filming location). Also, the ambulance is painted in the livery of the Ontario Ministry of Health.
* Revealing mistakes: When Ana and Luis are in the shower you can see their silhouettes. Ana's hair is too long, down to her waist - obviously a body double.
* Crew or equipment visible: In the beginning, when Ana is fleeing her home in a panic, a camera mount on the driver's side of her car is visible.
* Revealing mistakes: When Ana is escaping in the car and driving on the long street, we see a van crash into another car and throw it off the street before it explodes; though he should have been visible through the gaps between the houses, the van appears as if from nowhere at a very high speed, making it clear that he was digitally built in.
* Continuity: When Andre and Michael go outside to save the people in the truck, Michael shoots a Zombie when Andre's gun is empty. Michael aims at the zombie's stomach when firing, but we see the zombie getting hit in the head (which is far too high).
* Continuity: In the beginning, when Ana falls into the bathtub, the rod that holds the shower curtain falls across her lap. In the next shot, it is to her left, not across her lap at all.
* Continuity: The position of Nicole's arms as she hugs her father changes between shots.
* Continuity: When Ana tells Terry that the bathroom in Metropolis is fake, the position of her arms on the gate changes between shots. When she first calls him her hands are separated by a row, but when the camera comes in for a close up her hands are next to each other.
* Revealing mistakes: When C.J. pops the roof exit hatch to throw the propane tank, it comes all the way off, instead of swinging up and away as it's designed to do. In the overhead shot after the explosion, the hatch door isn't visible on the roof, but a few shots later (driving through the streets), it's back in place.
* Continuity: When Ana is pulling up to her home, you can see Vivian skating through the curve in the overhead shot. However, when she stopped at her driveway, the layout of the neighborhood shown in the overhead is different than in the level shot, and the cars in their neighbor's driveways are different.
* Continuity: When the bus driver tries to take Ana's car, she uses her left leg to push him away while presumably her right foot is planted on the accelerator. However, the shot from inside the car shows her right leg bent as if it's resting on the center console.
* Continuity: When C.J. tosses out the tank from the gun store its spout faces into the sewer grate. When they show the tank before he shoots to clear a path it is facing upward.
* Crew or equipment visible: When Michael is about to open the door to fight the janitor zombie, a close-up of the doorknob shows wires running across the floor when there was only water, a mop, and a "WET FLOOR" sign before.
* Audio/visual unsynchronized: When Ana walks into her room, she is talking to her husband. We see the side of her face and her mouth is not moving.
* Continuity: When Andy tries to fend off the zombies that get into his store (after Chips brings the food and radio), he shoots the door and the sliding panel that the zombies use. Later when they rescue Nicole, we see the bullet holes in the door, but the panel is undamaged.
* Continuity: When Michael comes out of the athletes store the blood is covering his entire front of his shirt but when he gets on the elevator it's just heavily splattered and not entirely covered.
* Crew or equipment visible: When the group enters Andy's gun shop to rescue Nicole, they first decide to replenish their ammo. Shortly after doing so, Michael turns to check the room for zombies. When the camera turns towards the back of the room, a crew-member can clearly be seen standing frozen behind the racks of clothing before quickly ducking out of the shot.
* Continuity: When the second group of survivors first arrives at the mall they all receive a bottle of water. When Steve, Michael, and Norma are talking, the cap on Steve's water bottle keeps coming on and off.
* Errors in geography: As pointed out on the DVD commentary, there are no mountainous islands in the Great Lakes like those shown during the closing credit sequence which is supposed to take place on Lake Michigan.
* Revealing mistakes: When the survivors escape in their armored buses as the dawn breaks, they are set upon by a horde of zombies. If you look closely, when one zombie is shot down, his shirt rides up slightly, revealing a very human, very healthy looking stomach, and not at all rotten like his face.
* Errors in geography: The call letters for the Milwaukee, WI television station covering the zombie attacks shown on the monitors in the mall were KBEX. The call letters should've started with a "W." For the most part, stations west of the Mississippi begin with "K" and stations east of the river begin with a "W" (like WGN in Chicago and WTMJ in Milwaukee). This mistake is also evident during the opening credits on the sign behind the news anchors and on the microphone of the on-location reporter. However, there are some exceptions to the "K-W rule"; KDKA, the first commercial radio station in the US and its TV affiliate, KDKA-TV, are in Pittsburgh (the rules for naming stations came later). Some stations in cities located on the Mississippi river (such as Minneapolis-St. Paul MN) may have their physical facilities on the "wrong" side of the river. However, all stations broadcasting in Milwaukee start with "W".
* Miscellaneous: When they are all on the roof of the building sending messages and food over to Andy, Nicole steals the truck. When they all run over to the side, you can see that terry's microphone has fallen off of his jeans in the back, and you can see him trying to fix it while running.
* Continuity: When Chips, the dog, is being lowered from the roof of the mall, to send Andy some food, he is secured with a red hook. The hook is latched in the first scene, but when Chips lands on the ground the latch is missing.
* Continuity: When Ana is in her car behind the bus, just before the driver tries to steal it from her, there is a shot of a nude woman stumbling past on the right hand side of the front window. There is a heavy smearing of blood on the window, obviously covering up the nudity. Only Luis' hand-prints on the left hand side had been visible before that point and it isn't there after she wakes up from the crash, either.
* Crew or equipment visible: In the scene during the birth of Andre and Luda's baby the shot switches between close-ups of Andre and Luda's faces. During one of the close-ups of Andre there is a cameraman and his camera clearly visible over Andre's right shoulder.
* Plot holes: When the group goes into the parking garage to turn on the generators they never make it. They are instead confronted by zombies who they douse with gasoline from a pump and set on fire. If there was no electricity in the garage then the gasoline pump wouldn't work.
* Revealing mistakes: During the end of the shot of the marina (near the end of the movie), one can see a boat driving off from a dock on the right of the screen.
* Anachronisms: When Luis hits the windshield on Ana's car, the pattern of cracks indicates that it's not made of safety glass, a government-mandated standard for all car windows since the 1980s.
* Continuity: When Ana runs into the restroom after being attacked by Luis in the beginning of the movie, we see the overhead shot of her falling into the bathtub. If you see closely the rug by the tub is folded in by Ana as she falls in, but when she gets out of the tub and we see her foot go down on the rug, it is normal.
* Continuity: When Luis jumps onto the windshield in Ana's car in the beginning of the movie, he spits up a bit of bloody saliva. When he goes to punch the windshield in, the spit disappears but reappears precisely where he punched the glass in, even though there is a few inches separation between the two spots. Later in the sequence, the bloody spot disappears again.
# Revealing mistakes: SPOILER: When Luda reveals her bite to Andre, she leans forward and her shirt falls forward revealing a jean line showing a very flat tummy, but her shirt is still very pregnant
# Audio/visual unsynchronized: SPOILER: Before Andy gets shot, Michael cocks his gun, but no sound comes out.
# Continuity: SPOILER: When Andre and Norma have their shootout when Luda is discovered to be a zombie, the shell casings from Andre's 9mm pistol land neatly at his feet while he's firing his gun, almost as if they are being dropped by hand at about waist height. In reality, 9mm shell casings eject up and to the right or left, not straight down
# Factual errors: SPOILER: When Ana shoots the baby zombie, she cocks back the hammer on the gun, but the black holes show that it is obviously empty.
# Plot holes: SPOILER: After Luda dies from her bite while she is in labor, you can clearly see the pulse in her neck still throbbing.
# Continuity: SPOILER: When Ana shoots Steve right after he is turned into a zombie she is obviously aiming at his torso, but when she shoots his head explodes.
# Revealing mistakes: SPOILER: At the end of the movie just after Ana takes Steve's keys and is running for the truck she ducks a zombie women but there is a male zombie near her. He switches sides between camera shots and he touches her as if to grab her but lets go he is obviously hesitating to give her time to get on the truck.