Goofs

The degree of the damage that was done to Baron Victor von Frankenstein's injured left eye changes from scene to scene throughout the entire film.

The film says that the Baron's ancestor's experiments began in 1740. "Galvanism" (a.k.a. electricity) was a central part of Mary Wollstonecraft Shelley's novel "Frankenstein; or, The Modern Prometheus" (1818) - but in 1740 Luigi Galvani was only 3 years old and his discoveries were not published until 1791. The use of cars, telephones and electrical devices in all of the previous Frankenstein films that were released before this one suggest that the experiments took place closer to the 1880s. No explanation is given for this mistake.

After examining the eyes of a victim, the Baron rejects them, saying that the victim possesses rare "type A" blood and thus they are a mismatch. He should have been more specific; type A-positive blood is very common, type A-negative blood much less so.

The Baron's monster has no eyes and is thus blind for most of the film, yet it seems to have no trouble both finding its way around the castle and searching for victims so that it can kill them in order to get their eyes for itself.

Whenever Baron Victor von Frankenstein's castle is seen from the outside in the film, it is a picture with scratches all over it.

A reel-to-reel tape recorder is shown several times to be recording Baron Victor von Frankenstein's description of his experiment's progress. However, the amount of tape on the recorder is fairly equally spooled on both reels in all of the scenes that it appears in, suggesting that this is, in fact, one scene that is repeated throughout the entire film whenever it appears in it.

During the Baron's first descent into the castle's crypt, a candle snuffer propped against the wall slides off.

When Baron Victor von Frankenstein is waving the scissors in front of Shuter in order to hypnotize him, the scissors are moving up and down in front of Shuter. When the camera is focused on von Frankenstein, his hand is moving forward and backward.

When Baron Victor von Frankenstein hypnotizes Mike, he tells Mike that when he hears the clock strike on the quarter hour, he will then go tell Carolyn that Douglas has arrived and is downstairs. However, when Mike does hear the clock, it strikes on the half hour instead and yet he still gets up to tell Carolyn that Douglas has arrived and is downstairs.