Continuity mistake: When Wolverine punches his lefthand claws into the wall, it is at bottom of a slab of concrete, and to the left of where four slabs intersect. When the shot changes, the puncture is now closer to the middle-right area of a slab.(00:13:16)
Continuity mistake: When the X-Men discover Jean and Annalee in the small room, neither Jean or Annalee are casting shadows on the wall behind them. When the shot changes, their shadows are now on the wall.(00:12:37)
Continuity mistake: When Leech telekinetically splits up the mob, on his left are a man with a light blue shirt, followed by a man with an orange shirt, and man with a light blue shirt behind him. On his right are a man with a green jacket and yellow shirt, a man with an orange jacket and pink shirt behind him, and lastly, a man with a blue jacket and yellow shirt. When the shot changes, the men have not only swapped sides, but now it is two men in light blue shirts in front of the man in the orange shirt, and the man with the orange jacket and pink shirt is now just wearing an orange shirt, and he is standing in front of the man with the green jacket and yellow shirt, and the man with the blue jacket and yellow shirt is in front of him.(00:06:05)
Continuity mistake: When Leech begins to telekinetically steal fruit from the vendor cart, he is stealing a red apple and what appears to be an orange with a yellow peel. When the shot changes, the orange is now orange in color, and as the two pieces of fruit move towards Leech, the orange is on his right, and the apple on his left. When the shot changes, the orange is now yellow in color again, and the fruits have swapped sides.(00:05:52)
Continuity mistake: After Jean and Cyclops first kiss after she tells him to relax a little, his left arm is around her shoulder and it suddenly jump cuts to his side with his hand in his pocket.(00:05:37)
Continuity mistake: When Reed asks Johnny if he found Sue, he is wearing a watch on his left wrist. When he sits down and puts his hands on his cheeks, the watch is missing.(00:10:02)
Continuity mistake: When Thing is quivering on the ground, Psycho-Man is just a step behind him. A couple of shots later, Psycho-Man has moved back several feet.(00:02:58)
Continuity mistake: When Reed is looking at the new element he just harvested, he is up against the table. When the shot changes, he is suddenly back a couple steps.(00:00:11)
Continuity mistake: When Maximus is telling Karnak to watch his words, Karnak is standing directly in front of Medusa. When the shot changes, he has moved to his left a couple steps.(00:14:15)
Continuity mistake: When Cyclops, Jean Grey, and Rogue enter the War Room to tell Professor X they are leaving for Genosha, the monitor Professor X is watching is level. A couple of shots later, the monitor is now slanted downwards.(00:08:04)
Continuity mistake: When Trask is approaching Storm and the other mutants, there is a cliff wall behind him. When the shot changes, it is now the sky behind him.(00:03:55)
Continuity mistake: When the Sentinel drops Storm, there is a female guard standing by its left foot. When Trask is approaching them, it is now a male guard by the Sentinel's foot.(00:03:49)
Continuity mistake: When the lead guard is explaining the inhibitor collars to the new prisoners in the wide shot, you can see Blob at the back of the group, and he is wearing tights, even though he is usually shown wearing a speedo.(00:02:24 - 00:03:41)
Continuity mistake: When Mandarin's hands first appear at the top of the cliff, he's not wearing any rings. A few shots later, he is suddenly wearing a ring on his right-hand ring finger. The ring then alternates between being on his finger and off for the remainder of the scene.(00:20:35)
Continuity mistake: When Iron Man picks up Arthur Dearborn by his collar, the left side of Dearborn's head is just outside the spotlight. When the shot changes, his entire head is in the spotlight.(00:10:54)
Continuity mistake: When Dum Dum Dugan is about to stand up and get in Iron Man's face, the control panel in front of him goes all the way up to his chest, whereas it only went as high as the middle of his stomach in all previous shots.(00:05:13 - 00:05:55)
Continuity mistake: When Dum Dum Dugan is showing Iron Man the footage of the school being set on fire, he sets his mug of coffee down on the control panel. A couple of shots later, the mug has disappeared.(00:05:14)
Continuity mistake: When Jubilee, Gambit, and Storm are first shown in their bungalow, there is a coffee table with a couple cups near the edge on the viewer's right, and some magazines on the top corner of the same side. A couple of shots later, the cups and magazines have all moved closer to the center of the table. When Gambit sits up, the magazines have disappeared entirely.(00:19:14)
Continuity mistake: When Storm, Jubilee, and Gambit are checking into their bungalow, the desk clerk has a rose on his jacket that is missing in a couple of shots.(00:13:10 - 00:13:51)
Continuity mistake: When Storm tells Gambit to put the discount placard back, he sets it in front of the clerk's computer. When the bellhop comes to get everyone's bags, the placard has disappeared.(00:13:24)