Continuity mistake: When Leonidas, and presumably all the other Spartans, use their spears to clear their shields of arrows after the arrow shower from Persian archers, the tips of the arrows are still visibly left on all their shields. In the next shot, when the Spartans regroup for the Persian cavalry charge, the arrow tips are gone. (Granted, this is a highly stylized movie based on a comic book, but that does not change the fact that this is a continuity error.)
Continuity mistake: At the end, during the fight scenes in the first class cabin, the number of overhead compartment doors that are open changes.
Continuity mistake: Saigo is told to empty out the chamberpot because it is full. But it is not full when he is taking it outside to empty it.
Continuity mistake: When Huo Yuanjia and Master Chen fight in the restaurant, Huo slices the top of Chen's head, yet when Chen is brought to his house the cut is gone.
Continuity mistake: In the school used to receive phone calls, a bald man to the left of the guy holding the phone gives a big puff to his cigar, creating a big cloud of smoke. Right afterwards, in a wider shot, all the smoke is gone.
Continuity mistake: When Paul (the hotel manager) finds Timmons in the kitchen when Timmons had been shot and is bleeding, we see Timmons with his hands on his blood that is on his shirt. When Paul comforts him, he puts his bloody hands on Paul's white shirt, but when we see Paul outside the hotel, there is no stain from Timmon's blood.
Continuity mistake: When the "Flag-Raisers" begin stripping down to go swimming, they show a few of the Marines already down to their boxers. They switch to a shot of Bradley and then back to the Marines and all have their pants on.
Continuity mistake: When Louis Simo is unconscious on the floor, his girlfriend enters and the keys next to his head change position in the next shot. (01:16:20 - 01:17:05)
Continuity mistake: When Teddy has delivered Damien's letter to Sinead, he puts his cap on, gets on his motorcycle and puts his pair of goggles on the handlebar. The scene then cuts to a wide angle and the goggles are around his neck.
Continuity mistake: At the end when Marie is sitting in the bed and the knock at the door startles her, her dressing gown is off her shoulder and then up on her shoulder when she sits up.
Continuity mistake: When the Prime Minister is preparing to make his golf swing, his shawl is alternately bunched up and then spread out smoothly.
Continuity mistake: When Ahmed Alhaznawi (the tallest of the four terrorists) has just gotten through the metal detector, a pattern of light appears on the floor behind him between shots.