Revealing mistake: In the scene where Sonja's sister is escaping from the temple she is shot with an arrow whilst on an aerial slide. Her body hangs limply and is met at the end of the slide by Kalidor. However, the limp body is a stunt *man* in drag.
Continuity mistake: How come Red Sonja asks the little prince and servant for directions and she takes the quickest route, yet the same prince and servant get ahead of her?
Continuity mistake: In the scene where Red Sonja is fighting some guy in front of her Master, you see it from her point of view. When she points the sword at the guy after she disarmed him, it's clearly to see that the arms belong to a man, as they are large and hairy. In the next shot, you see it from another angle and you can see her arms are placed in another position and its easy to see that it wasn't her arms in the shot before.
Revealing mistake: Sonja has a modern vaccine scar on her left shoulder.
Continuity mistake: Near the end, when Red Sonja and Queen Gedren are sword fighting, the scar on Gedren's right cheek is missing.
Revealing mistake: When Kalidor lifts Prince Tarn into the air with one arm, the cables attached to Tarn's back are visible.
Revealing mistake: When the High Priestess gets hit by Ikol's Shuriken star the guiding wire for the projectile is visible.
Visible crew/equipment: When Varna is shot by the arrow whilst on the areal slide you can see the arrows guiding wire.