Continuity mistake: Robin, in his escape from the scaffold, pauses on his horse before the portcullis and exhorts his men to return to Sherwood. He then rides over to the right, draws a sword from behind him and slashes through the rope which activates the portcullis and rides the rope to the top of the wall. No sword is seen on the horse when he is exhorting his men.
Continuity mistake: In the final swordfight, Basil Rathbone lunges past Errol Flynn, who dodges him and leaps to the floor below. Rathbone continues on dropping his sword at the base of the steps. In the next cut, however, the sword lies between Rathbone and Flynn - a good eight feet away - allowing Robin Hood to pick it up gallantly and offer it back.
Continuity mistake: In the scene near the beginning when Robin is in the "great hall" -- a spear is thrown at his chair. He arises in time to avoid injury, but the spear goes through the back of the chair. However, the next time you see the chair, there is no hole in it.
Continuity mistake: When Robin escapes from hanging, he jumps from the scaffold onto his horse and rides off, all with his hands tied behind his back. When he jumps, just briefly before the shot changes, you can see his hands break the breakaway bindings and grab the horse's saddle.
Continuity mistake: In the feast in the forest scene which occurs after Robin Hood and his men capture Sir Guy's entourage, Robin sits next to Marian and offers her a roasted bird. She refuses the bird, but when the camera cuts back to Robin he has a mutton leg. Next the camera goes back to Marian who looks at Robin who now has the bird again.