Wheelchair-bound mad scientist Dr. Durea (J. Carrol Naish), the last descendant of the original Dr. Frankenstein, takes to murdering young girls for experimentation in hopes of perfecting a serum of his own creation with help from his mute assistant Groton (Lon Chaney, Jr.). Count Dracula (played by Roger Engel under the pseudonym "Zandor Vorkov") comes to the scientist, promising to help him revive Frankenstein's monster (which he has exhumed from its secret grave in Oakmoor Cemetery) in return for Durea's serum which he hopes will grant him immunity to sunlight.
As a cover, the duo work out of the Creature Emporium, a throwback to the old side show days located on the boardwalk amusement park in Venice, California. They bring the Monster (John Bloom) back to life and send him out to exact revenge on the man who discredited and crippled Durea, Dr. Beaumont (Forrest J. Ackerman). Las Vegas showgirl Judith Fontaine has also arrived, looking for her missing sister Joanie who was last seen hanging out with a group of hippies led by Strange (Greydon Clark). Judith has gotten no satisfaction from Sgt. Martin (Jim Davis). She says she is going to investigate on her own and does so, attracting the attention of biker Rico (Russ Tamblyn) and his gang. Rico slips her some LSD at a dive bar and Judith, while on a trip, is taken by Strange and his girlfriend Samantha (Anne Morrell) to the home of aging hippie Mike Howard (Anthony Eisley) who agrees to help her find Joanie. Judith, Mike, Samantha and Strange go to the Creature Emporium and show Durea a picture of Joanie, but he says he has never seen her.
More girls turn up missing, the Monster kills a couple of police officers and Groton takes to the beach with an ax and kills Rico and his gang who were attacking Samantha, then Groton takes her inside the Creature Emporium. Judith and Mike go to the Emporium and confront Durea who explains that the girls (including Joanie) were frightened before their deaths and this created an enzyme in their blood which is the main ingredient for his serum. He also tells Judith that, after he has Mike (with whom she has fallen in love and he with her) killed, her fear will help him complete the serum at last. Durea sends Groton and the dwarf Grazbo (Angelo Rossitto), the ticket taker at the Creature Emporium, after them (Durea's original reason for creating the serum in the first place was to heal his damaged legs and to make Groton and Grazbo into normal people). Grazbo falls through a trap door in the laboratory which leads to the beach below the Emporium and onto an ax he had dropped, which kills him, and Groton goes after Judith. Sgt. Martin and Strange arrive with the police and Martin shoots Groton from the rooftop of the building from which he falls to his death, while Durea falls from his wheelchair into a guillotine in the Emporium while attempting to escape and is beheaded in it.
Dracula confronts Mike, who sticks a lit car flare in the Monster's face, forcing him to briefly turn on Dracula in his pain. As Mike is running away with Judith, Dracula blasts him with fire shot from his demon-headed ring, burning him to ashes.
Judith faints and awakens to find herself tied up in an abandoned church outside of Venice where Dracula's coffin is located. Dracula is about to make her his vampire bride, but the Monster (who has fallen for her beauty) wants none of it and forces Dracula out of the church and into the woods (but not before removing Dracula's ring from his finger), where a fierce battle ensues between the two monsters. Dracula literally rips off the Monster's arms and head, but gets caught in the rays of the sun before he can make it back to his coffin and crumbles to dust. Judith manages to free herself and picks up Dracula's ring, but drops it and leaves in fear.Lon Chaney, Jr. as Groton
J. Carrol Naish as Dr. Frankenstein
Zandor Vorkov (Roger Engel) as Count Dracula
John Bloom as Frankenstein's monster
Jim Davis as Sergeant Martin
Regina Carrol as Judith Fontaine
Russ Tamblyn as Rico
Anthony Eisley as Mike Howard
Anne Morrell as Samantha
Maria Lease as Joanie Fontaine
Angelo Rossitto as Grazbo the evil dwarf
Forrest J. Ackerman as Dr. Beaumont
Gary Graver, the future cinematographer for Orson Welles, is an extra in the film.
Greydon Clark as Strange
Shelley Weiss as the Creature (the "Creature" is actually the Monster in the scenes taking place in the church and the woods)
William Bonner as biker #1
Bruce Kimball as biker #2
Albert Cole as cop killed by the Monster
Gary Kent as Bob the beach boy
Connie Nelson as Laura the beach girl
This was Lon Chaney, Jr.'s final horror film role and J. Carrol Naish's last film. Chaney filmed his part in mid-1969 when the film was titled The Blood Seekers. Naish filmed additional footage in 1970 when Dracula and the Frankenstein Monster were added to the story (in his confrontation scene with Dracula, he appears noticeably older). Director Adamson's wife, Regina Carrol, appears in the film as Judith Fontaine, one of the people who discover the two title monsters. The film was released on DVD by Troma Entertainment and later by Media Blasters under its "Shriek Show" imprint in widescreen and HD for the first time. Cheezy Flicks also released it on DVD as well.
Two other films titled Dracula vs. Frankenstein were made around the same time as Adamson's film. In 1969, Spanish horror film icon Paul Naschy starred in Los Monstruos del Terror which was later released on VHS as Dracula vs. Frankenstein. Meanwhile, in 1972, famed Spanish schlock film director Jesus Franco turned out his Dracula vs. Frankenstein (also released as Dracula, Prisoner of Frankenstein), apparently unaware that Al Adamson was already using that title.
The film was met with negative reception from critics, with the most prominent critique being the overwhelming amount of darkness in the movie, making it hard to see the action.