Continuity mistake: When Sarah gets those cuts on her head, they seem to dissappear or get smaller in number as the movie progresses. (01:03:15 - 01:18:05)
Factual error: When Hammond is talking with Malcom about going to Site B he says that the departure is from San Diego which is "a couple of hours" away from there. A flight from San Diego to Costa Rica would take over 5 1/2 hours. Then there is the trip to the island.
Factual error: After Ian and his girlfriend get the baby T-rex from holding in San Diego, they track down the big T-rex. They pull into a gas station and the Trex knocks the large 76 ball towards them. The problem with this is that that gas station/intersection is not in San Diego, CA but in Granada Hills, CA. The cross streets are Rinaldi and Balboa. (01:49:00)
Continuity mistake: When Sarah, Malcom and his daughter argue in the trailer for the first time you can see out of the back window. It shows they are right in front of a thicket of trees a few feet behind the trailer. When they step outside a minute later to see the InGen choppers arrive you see that the trailer is pulled up on the cliff tops already. The only view you should have seen out of that window was open sky as the window points out to sea. (00:32:10)
Visible crew/equipment: When Sarah is returning the baby T-rex to the parent dinos, just as she is about to release the baby so it can "walk" back to its parents, look at the bottom of the screen. You can see someone's head pop up for a second, presumably a crew member taking the animatronic baby from Sarah. (00:55:55)
Continuity mistake: The cracks in the rear window of the lab truck when it's hanging over the side of the cliff seem to vary between the shots outside underneath vs shots inside as to where they are in the glass. There is a major one above (not underneath) Sarah's hand that's visible from inside and not from underneath.
Continuity mistake: Towards the beginning where the girl goes to photograph the Stegosaurus, the scene cuts back to her boyfriend and the guy with the video camera. In two cuts to their scene while the girl is photographing and interacting with Stegosaurus, the guy with the video camera opens the flip out LCD on the video camera and starts shooting the action. (00:24:50)
Visible crew/equipment: When the two T-rex's surround Eddie's car one bites the roof off if you look to the right side of the roof once in the T-rex's mouth you will see a large wire obviously so the model and the roof don't fall over.
Continuity mistake: When the movie starts and the little girl is surrounded by mini dinosaurs, her father lowers his Financial Times newspaper twice. First in the closeup he lowers it to his lap, and then at the start of the next wideshot the newspaper is back up in front of his face when he lowers it again before it drops onto the sand. (00:02:40)
Revealing mistake: When the dinosaurs are released from their cages and are running around the camp, a jeep is launched into the air and lands almost on top of the 2 hunters who leap from the tree. When the jeep falls forward, and down out of the tree the bottom of the tree moves and shakes in a way it shouldn't if it was truly made of wood.
Continuity mistake: When the crew are looking for Sarah, Eddie is holding the tracker and Ian is holding the rifle. In the next wide shot where they watch the Stegosaurus cross the river Eddie is now holding the rifle and Ian the tracker and the bag. The scene cuts again to the close up and Eddie is again holding the tracker. (00:22:00)
Revealing mistake: As the T-Rex rages through the street, some cars crash, and one reversing car dramatically flips. Two problems though - firstly, it's reversing quickly enough to mean it must have travelled past the dinosaur to build up that much speed, so the driver would have just driven forwards away from the T-Rex instead. Plus there's nothing which would realistically be in the road to make the car flip over like that, it's just a street with cars stopped on it.
Continuity mistake: When Stark is separated from the group and is attacked by the tiny dinos, his last desperate attempt at escape shows him going down a small stream, then over a log, where he falls and is killed. In the next shot, we are looking at the same log from the other side and bloody water is moving down stream with Stark's body on the other side. He can't be on both sides of the log at the same time.
Factual error: When Eddie is pulled from the car, it zooms forward and goes over the cliff. In reality this wouldn't happen. Right up until his death, Eddie had the car floored in reverse. Once he took his foot off the pedal the engine would have stalled. If a car is in gear and the clutch isn't depressed then the wheels won't turn (especially on wet mud!) The trailer would have had to drag the car but the wheels are shown turning freely.
Factual error: When the T-Rex grabs Eddie out of the car, as soon as it takes its foot off the hood the car shoots forward and both it and the trailers fall off the cliff. In reality this wouldn't happen, the trailers would have simply started sliding again slowly. It's also shown that the cars wheels start turning faster as the car picks up speed going forward. Eddie had the car in reverse, as soon as his foot came off the pedal it would have stalled meaning the wheels wouldn't have turned and instead it would have just been dragged like it was doing before he got back behind the wheel.