Continuity: In the scene where Inga, Fredrick and Igor throw the net over the monster, Inga sticks the syringe of the sedative in the monster's back but does not push down on the top, yet the monster still falls over. A few seconds later when she collapses on the monster, you can see all of the fluid inside spray out.

Continuity: When Igor is holding onto the cemetery gate, his hands swap between angles from holding two bars close to each other, to having an empty bar in between.

Revealing: Right before Doctor Frankenstein (Gene Wilder) gives life to his creation he is standing behind the monster on the platform giving his speech. While he is giving his speech you can see the "dead" monster breathe, not only once but several times.

Factual error: The movie is set in Transylvania, but the natives all speak German and with German accents (probably an homage to the book, but still incorrect).