Continuity mistake: Wolverine fights the Blob in the boxing ring and knocks him out. When he interrogates the Blob on the whereabouts of 'the island' he draws his claws in a horizontal line, but when the shot switches back (beside Wolverine's shoulder), his claws are in a vertical line facing the Blob's face. The alignment of the claws switched from horizontal to vertical every time the shot changes.
Continuity mistake: After Logan is shot twice in the head with adamantium bullets by Stryker , an overhead shot of him shows the bullets at different heights on his forehead. In this shot, the bullet on his right is noticeable higher. After Logan sits up and they begin healing, the left bullet appears higher on his forehead at an almost even height to the right one.
Continuity mistake: In X-Men 2, when Wolverine re-enters the room where he had the adamantium grafted to his body, there are numerous claw marks on the walls and water bath which have obviously been made by him (3 marks, ie. his claws - Deathstrike would have made 4 or 5). In this film he just gets up and runs out of the room, doing nothing to justify where the claw marks come from.
Continuity mistake: When Wolverine has been catapulted from the truck, Wolverine looks to the right as if to slash the helicopter blades on the right side. Viewing from above the chopper the blades are spinning counter clockwise initially. Once Wolverine reaches the chopper blades, the blades are spinning clockwise, enabling him to slice and dice.
Continuity mistake: When Logan and Sabretooth stand back-to-back during the fight with Deadpool, watch their positioning: Logan's left hand is directly above the edge that leads down to the inside of the reactor. But after Deadpool jumps over them and starts hitting Sabretooh, Logan is now positioned so that his right hand is directly above the edge.
Continuity mistake: In the scene where Wade (as the Mutant Weapon XI) & Logan's show down begins, Logan's claws release slowly, and in retaliation, Wade gets his Right hand's sword out. This is the front view. After Striker types in the command to "engage", the front view for Wade still shows only the right sword out. However, when the camera angle shifts to the left profile of Wade attacking, both the swords are out.
Continuity mistake: When Team X is in the African village trying to find the adamantium source, Victor is about to kill a man and Logan stops him. In the first shot, Logan says " Don't even think about it " and Victor's thumb claw on the hand Logan is holding back is very different than in the rest of the movie, as it appears to be coming out of the very tip. As the shot switches between Logan and Victor for the rest of the conversation, his thumb claw looks the same as in the rest of the movie.
Continuity mistake: When Logan takes out the helicopter carrying Zero, as it crashes and rolls you can see a pair of legs coming out of the window. As the helicopter rolls, the body almost entirely comes out, though when Logan gets up close, the pilot is slumped in his seat, with his limbs protruding only slightly from the wreckage.
Continuity mistake: At the end of this movie Wolverine is shot in the head, making a hole in his adamantium skull. However in X-Men we saw an X-ray of his skull, and there was no hole in it. Logan's skull and brain would've healed from the adamantium bullet fired by Striker, but the bullet hole in the adamantium forehead plating should have been visible in the X-ray image.