Audio problem: When Bunny (Ramon) is, as Zorro, spelling out "Zorro" on the wall with his whip, the number of whiplash sounds does not match the number of marks in the wall.
Continuity mistake: When Charlotte Taylor Wilson arrives by stage, Don Esteban is making a speech. Behind him is a shield over the gateway. In most shots, the shield is in full sun. But in a couple, it's partially in the shade of some trees.
Continuity mistake: When Zorro and Valasquez ride into the tree branch and are knocked off their horses, they lose their swords. When the get back up, their swords are in their hands.
Continuity mistake: One bowl of apples which gets shattered reappears intact in the following shots.