Continuity: Near the start in the museum, when Pyro is asked for his lighter and refuses, watch him playing with his lighter. One shot shows the top flipped open away from him, but when the angle changes it's facing towards him. There's no time it's out of shot for it to move.

Revealing: In the beginning of the movie when Wolverine puts the cigar out in his hand, you can see the mark of a wedding ring on his ring finger (Hugh Jackman is married). Even if Wolverine got married during the "blurred" bit of his memory so doesn't remember it (tenuous at best), his healing ability would have removed any ring mark. Either way it just doesn't belong.

Continuity: When Mystique is looking around in Stryker's computer, she notices a folder marked "Cerebro", next to the "Delete" icon on the screen. However, when she opens the folder, we cut to a wide shot and the icons around the delete icon have renamed themselves, plus the cerebro folder itself has disappeared.

Deliberate "mistake": Almost trivia, but not quite. When Mystique's looking through the guard files to find a suitable candidate, lots of photos flash up very quickly before she finds the guy she uses. Of note is that Bryan Singer pops up in guard uniform (with his own name), and so does someone called "Donner, L". This is most likely referring to Lauren Shuler Donner, one of the producers, and sex is specified as "F", but the photo is of a stubble-coated man.

Continuity: In the scene with Wolverine and Bobby at the mansion when Wolverine can't sleep, when he hands Bobby the soda bottle the contents are almost full but when bobby blows on the bottle and hands it back to Wolverine the contents are at the bottom of the bottle neck. Then when Wolverine drinks the Dr Pepper, the bottle is full again.

Continuity: When Wolverine attacks the SWAT member in the Mutant Academy kitchen while Iceman takes cover, there's a spot the difference competition between the start and end of the gunfight. After a second or two there are bullet holes in the back wall, the Dr. Pepper's been knocked over, the basket's gone from the corner of the table, and the chair at the right is maybe a foot from the corner. When we cut back, the bullet holes in the wall have changed position, the Dr. Pepper's righted itself, the basket's back on the corner, and the chair's now much closer to the edge. All this while Iceman's hiding and Wolverine and the gunman are fighting each other.

Continuity: In the scene where Wolverine is talking to Stryker in the mansion corridor, Bobby creates an ice wall between them, including the wall. Shortly afterwards when they leave and Bobby takes his hand away, the wall suddenly has no frost on it at all.

Revealing: In the scene where Storm and Nightcrawler rush to rescue the children from the holding cell, you see a shot of the cell where the children stand up and say "Listen..." before Nightcrawler teleports inside. If you look carefully, you will see Nightcrawler's silhouette in the shadow against the wall.

Continuity: In the end, when the President is visited by the X-Men, he receives a blue binder, which is laid in front of him on the table. When they have left, you see a shot including the President's desk, and you can see that the only thing he has on the table are some sheets of paper, stapled in the upper left corner, opened up. Then the shot changes to a close-up of the President, and then back again, and you see the blue binder in front of him, closed, and the papers have disappeared.

Continuity: When Jean and Storm first meet Nightcrawler and hold him mid-air, you can see his coat fall down ("up" by his view) when you're looking at him from their point of view, but when the camera is on the other side, the coat is sticking to him so you can see the two of them.