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).

Continuity: When Dr. F arrives at the train station there's a lot of smoke/fog around him. In the close-up that comes a split second later it's all gone.

Continuity: The brain that Frankenstein draws on the blackboard in the first scene is different from the one behind him as he is seated and lecturing. Check the shading on the brain stem.

Continuity: At the castle, Dr. Frankenstein throws darts while talking with Inspector Kemp. The shot of the darts hitting the board does not match with the shot where Inspector Kemp takes the darts back from the board.

Audio problem: When Frankenstein first opens the door to the monster-making room, the rusted handle breaks into two pieces, but when he throws them down, only one piece can be heard hitting the floor.

Continuity: As the townspeople gather to storm the castle, the clock in the town square shows 10:30. When the Inspector steps out of the building to address them, the clock over his shoulder shows 10:00 PM.

Continuity: During the scene where the blind man, Gene Hackman, is serving soup to the monster, the blind man spills 2 large ladles of soup onto the monster's lap. The blind man then burns the monster by lighting his thumb, thinking it's a cigar. The monster screams, and breaks through the front door, leaving the blind man's cottage. When the monster leaves the cottage, there is no sign of the spilled soup on his clothes.

Revealing: For most of the opera house stage presentation, the monster is a full head taller than Friedrich. During the tap dance, however, they're the same height. Although the camera angle/depth of field used tries to disguise this by keeping Gene Wilder in the foreground for most of the shots, it's still apparent that Peter Boyle isn't wearing his probably-impossible-to-dance-in platform shoes during the sequence.

Continuity: As he's about to depart at the train station, Friedrich leans in to try and kiss Elizabeth good-bye. He's mere inches from her nose when the shot cuts, at which point he's suddenly standing more than a foot away from her.

Continuity: When Dr. F meets Igor and says "You were sent by Herr Falkstein, weren't you?", the expression on Igor's face from a side view doesn't match the immediate following the front shot (smiling / serious). The rest of the shots changing back to front do match.

Continuity: At the cemetery gate, Dr. F tells Igor to crouch, which he does but very slightly. In the following angle Igor's position is totally different, being crouched at ground level with his hands on a different place.

Continuity: Dr. F arrives at the train station and stands to the left of the candle light. A second later he is right in front of it.

Continuity: When Dr. Frankenstein breaks the door handle, there are two pieces in his hand. The next shot shows him holding only one.

Continuity: At the breakfast table while planning how to make the new monster, shots on Inga's face have an mostly dark background, but angled shots on her and Frankenstein show an illuminated background behind her.

Continuity: During his lecture on the brain, Professor Frankenstein draws the medulla oblongata on the black-board twice.

Revealing: One of Peter Boyle's teeth on his lower jaw was painted black for that "broken grin" look. It can be seen reflecting in some scenes: when Frankenstein enters the cell with the monster and it cries, and later when the monster screams while killing the jailer.

Visible crew/equipment: After the monster catapults little Helga from the seesaw to her room and she is tucked into bed, it is possible to see the wire that was used to pull the covers up (when her parents enter the room).