In the prologue explaining what happened in the first Frankenstein (1931), a man is shown in close-up being strangled by the monster; however, the monster's sleeves are torn and his arms already burned by the windmill fire. Clearly this close-up was newly filmed and inserted as if from the 1931 movie.
During the prologue, there is a medium close-up of Shelly in his chair with Byron's arm behind him, even though Byron is standing too far away to do so. The shot in question was from earlier in the sequence when Byron briefly stood beside Shelly.
After Dr. Pretorius shows a queen, a king, an archbishop, a devil, a ballerina, and a mermaid that he has created and placed in jars, a rear view of the table on which they are sitting also shows a jar with a baby in a high chair, who is not in other shots. But, in post production it was decided to cut the introduction of the baby. It would have been too expensive to retake the relatively brief long shot that included the baby.
While the Monster is trying to keep the shepherd girl from screaming, his hand is alternately on/off her mouth between shots.
When the two hunters first discover the Monster in the hut with the blind hermit, one of them has a rifle and begins fumbling with it in an attempt to shoot, but drops it when the Monster knocks him down. He also loses his hat in the tussle. The hermit intervenes, but the hunters tell him that his 'friend' is a murderer and the Monster, hearing this, moves toward them again. The hunter then inexplicably has his hat back on his head and the rifle back in his hand and is hurriedly trying to cock it. As the Monster closes in, the camera pans back, showing the hunter now without his hat and rifle again and instead hiding behind a column. The quick scene of the hunter hurriedly trying to cock the rifle should be placed earlier in the sequence, when the hunters first appear in the doorway, and before the Monster knocks the hunter down.
At the end of Frankenstein (1931), the injured Henry is taken back home and resting in bed when the film ends. Yet at the beginning of this movie (following the Shelley/Byron prologue), Henry is still at the windmill and wounded. Since Frankenstein (1931) was still in circulation, new prints were released that excised the happy ending. So there were no continuity issues - at least, not in 1935.
As the film begins, Mary Shelley is telling people the story of Frankenstein in 1818. Yet the main story, which is presented as flashback, is clearly set in the 1930s. Director James Whale likened the setting of the film to a "fairy tale", one that takes place outside normal time, and thus included deliberate anachronisms.
Many people think it incorrect to refer to the The Monster as "Frankenstein," the same name as his creator. In the prologue, Lord Byron states that The Monster's name IS Frankenstein in this series.
When Elizabeth is talking to Henry on the telephone, you can see her hand slip out of the ropes that have her tied up, then slip back inside the ropes again.
When Karl and the monster are climbing up on the parapet, the background can clearly be seen through their figures.
When the monster is at the pond getting a drink of water, his reflection as shown is not a mirror image as it should be, but a normal front view of his face.
When the monster is being chased by the mob (before they can catch him), he rolls a heavy boulder off a cliff, on them. The boulder is bumped by one of the villagers, and moves easily, showing it to be probably nothing more than a large ball of papier-mâché.
The bride has far too much hair to fit under the bandages shown before her unveiling.
The setting of this movie is 1816, the year Frankenstein was written by Mary Shelly. At one point the monster is wandering through the woods and scares a woman. Two hunters hear her screams and shoot the monster in the arm. The weapon they are hunting with is a percussion firearm, which uses a percussion cap to ignite the main charge. BUT the percussion cap was not invented until 1822, some 6 years in the future.
In the final shot of Minnie talking through the prison window, her mouth movements don't match her words.
When the blind hermit plays the violin he does not move his fingers when the notes are changing.
When Pretorius states, "Nothing, that is, except what He demands" as he approaches Frankenstein after warning everyone to say nothing, his mouth does not move.
Even though this story takes place directly after the first film, the Burgormaster is clearly a different actor than in the first film.
This is a direct sequel to Frankenstein (1931), yet Henry's father, Baron Frankenstein, who was featured prominently in the first movie, never appears. A character's dialogue briefly implies that Henry is the new Baron, which would imply the death of his father. But if his father had passed away, it would have been a major plot point or given some emphasis. And in the original script, there was much ado made about the elder Baron's death, from shock and grief at Henry's apparent demise. But the scene was cut from the final release print.
At the start of the film, the angry villagers hunt down Frankenstein's Monster and are able to subdue him and tie him up, leaving him chained in a jail cell in the town. However, once he escapes, everyone flees in raw panic, with no attempt to overcome him a second time.
The film is a direct continuation of Frankenstein (1931), yet in that first film, Maria's father is named Ludwig. In this film he is named Hans and is played by a different actor. (This wouldn't be an issue if the actor who played Ludwig wasn't clearly shown in the recap of the first film.)
Despite being greeted at the door by the housekeeper saying that Herr Frankenstein "is in his bed - where all decent folks should be at this time of night," and Herr Frankenstein being already in bed, Dr Pretorius invites him to visit his house "tonight; it is not very late."
Pretorius tells the Monster that cigars are his "only weakness," in another part of the movie he tells Henry that gin is his only weakness.