Goofs:
Audio/visual unsynchronized: When Inspector Krogh fires his last shot at the monster, there is no corresponding gunshot on the sound track. (more)

Trivia:
The character of Ygor (played by Bela Lugosi in the final film version) does not appear in Wyllis Cooper's October 20, 1938, draft of the screenplay titled "The Son Of Frankenstein". Director Rowland V. Lee was annoyed at Universal's low-balling of Bela Lugosi (who was being paid only $500 per week because he desperately needed a job and Universal knew it), and he kept rewriting the script to make Lugosi's character more central, and to make sure that Lugosi ended up with a decent salary. The "Ygor" character died in the film, but returned in the sequel, The Ghost of Frankenstein (1942); for unknown reasons, the spelling of the name was altered to "Igor" in the credits (yet the script for the even later _Frankenstein Meets the Wolf Man (1943)_ reverted to the original spelling "Ygor." (more)

Quotes:
Inspector Krogh: One doesn't easily forget, Herr Baron, an arm torn out by the roots. (more)