Continuity mistake: While Dastan is securing the second gate in the battle for Alamut, a ring appears on his finger. While he is levering the gate, there are no rings on his finger. A moment later, when he waves at Bis to signal the gate is secure, he wears a silver ring on his left hand. The ring is visible again when Bis waves his torch at him, but is gone the next time we see him. (00:12:10)
Continuity mistake: After being chased by soldiers after talking to his uncle, Dastan gets into a swordfight with Garsiv. As soon as it starts, Garsiv hits a pillar with his weapon knocking a significantly large chunk and a another smaller chunk out of it. In the immediate shot, the size and locations of the two chunks differ.
Continuity mistake: While storming the eastern gate of Alamut, Dastan climbs up onto a high beam with some rope. He then ties the rope around the beam and in one shot, the part of the rope that Dastan is holding onto is on the left hand side of the beam. The shot then changes to the right side of the beam and the rope has suddenly switched sides.
Continuity mistake: When Prince Dastan began to flee from the Persian soldiers after his talk with his uncle, one of the soldiers cut Dastan's left arm, with a noticeable bloody cut. But after Dastan escaped the soldiers and leans against a wall, the cut and the blood was gone, with his left arm undamaged.
Continuity mistake: In the scene where Dastan and Tamina are again captured by Sheik Amar, Seso, and their group because of the chaos they caused back at the valley. In the oasis, watch Dastan's left arm carefully: the leather belts are changing shot by shot. In one shot there are many black strips across, and in another shot we see it's a single black strip running around his arm.