Christopher Lee tried to talk Peter Cushing out of doing the film, as he considered it to be beneath an actor of Cushing's status. Lee told Cushing that Ralph Bates was willing to step in and do Cushing's role of Professor Lawrence Van Helsing if Cushing did not want to do it, but Cushing replied that he thought the change of scenery might help his depression after struggling with his wife's death two years previously.
Speaking in an interview in the late 1990s, director Roy Ward Baker personally described the making of this film as "a nightmare". He said it was only when he and his fellow Hammer film crew got to Hong Kong that he discovered that almost none of the Golden Harvest studio crew spoke any English. He also said that he was unaware that Hong Kong-made films were shot silent and then looped in post-production due to the constant noise of traffic and aircraft and when he started filming they found out the hard way that the location sound was practically unusable for the same reason, finding a green field to use as a backdrop for one key scene was particularly problematic due to the lack of such a space (eventually, he was able to film close to the mainland Chinese border but had limited use of camera angles due to the modern city in the background) and that Peter Cushing was practically catatonic, having recently been widowed but still wanting to be in the film in order to give him something to do while he was in mourning.
This film was the first of two Hammer films that were shot back-to-back in Hong Kong and the fifth and last film in the Hammer "Dracula" series in which Peter Cushing played Van Helsing.
Although Christopher Lee was offered the role of Dracula in this film, he turned it down after reading its script.
This is the only film in the Hammer "Dracula" series to not have Dracula's name in its title.