Continuity mistake: When Erica eats the cat the telephone is on its side, then the right way up.
Revealing mistake: At the very end, a bat flying out of the mist toward the camera was intended to imply that Barnabas had taken bat form and could thus be around for a sequel. But through the haze, Barnabas can still be seen lying on the floor when the bat flies past. (01:36:25)
Continuity mistake: The footage of Dracula impaled on a giant golden crucifix at the end of 'Dracula Has Risen From The Grave' is re-cut for the pre-credit sequence of this film. However, when the second film continues, the golden crucifix is missing in the background, behind Dracula's powdered blood and collapsing cloak, creating a continuity error with perhaps an unusual reason for happening. Hammer props department may have rid themselves of the crucifix between films shot a year apart.
Continuity mistake: Paul enters the castle in Dracula's coach. When he gets out of the coach and walks around a bit, the coach with the horses has suddenly disappeared.
Revealing mistake: A Nineteenth century social occasion is taking place at a mansion in the evening. The lead female vampires servant arrives by horse in front of the mansion and in the background you can see some modern tennis courts with metal gates and fences. The nets have been removed but the appearance of the courts can still be seen. (00:10:35)
Continuity mistake: When Dr. Brockton is descending into the cave her hair changes from one style to another.
Factual error: The film is set in 16th century England. In the first scene, when the accused girl is branded, she screams, and reveals a full set of teeth with nice silver amalgam fillings. (00:03:35)
Continuity mistake: Professor van Helsing and Doctor Seward enter the Harkers' bedroom. A few seconds later, they enter the bedroom again. (00:52:00)