Continuity: Diana holds the crucifix out towards Dracula twice in successive camera shots from the back while front shots don't show her holding it at all
Audio/visual unsynchronized: Klove cuts Alan Kent's neck and you see and hear blood falling onto Dracula's grave. The camera cuts back to Kent, whose hanging upside down. Blood can be heard dripping rather quickly, but none can be seen.
Revealing mistakes: Just as Dracula begins his descent into the freezing waters of the castle moat at the end of the film, the long shot clearly reveals the pivots holding up the ice beneath him.
Errors made by characters (possibly deliberate errors by the filmmakers): Father Sandor blames the local priest for being a "superstitious frightened idiot" but later on he admits that "vampirism...an undisputed fact".
Anachronisms: A jet aircraft trail can be glimpsed in the sky during the climax.
Continuity: After the tourists enter the castle, the coach drives away and the gate shuts. Charles runs towards it, while the others stand in the foreground, to his left. When he walks back, the camera cuts to a slightly different angle. Diana, Helen, and Alan are now standing further to the right.