In 1780, at Count Dracula's Transylvanian castle, African prince Mamuwalde and his wife Luva ask the count to sign a petition abolishing slavery, but the count scoffs at the suggestion. He instead condemns Mamuwalde to eternal life as an undead, a vampire like himself, naming him “Blacula.” Sealing the coffin, Dracula leaves Luva to die in the dungeon with her husband’s coffin. Over 190 years later, flamboyant interior decorators Bobby McCoy and Billy, charmed by the gothic allure of the count's deserted mansion, buy the entire contents, including the coffin, and ship everything to New York City. Unlocking the coffin at their New York warehouse, both men are then bitten and killed by the blood-starved Mamuwalde. After the dead men’s bodies are discovered by the police and taken to separate funeral homes, sisters Tina and Michelle and Michelle’s fiancé, police pathologist Dr. Gordon Thomas, pay their respects to their friend Bobby. Gordon becomes suspicious when he sees the two bites on the dead man’s neck and notes the absence of any blood in the body, despite mortician Swenson’s claim that the body was not drained or embalmed. On the street that night, Mamuwalde sees Tina and chases the terrified woman, but is struck down by a passing cab. Unscathed but infuriated that he has lost Tina’s trail, Mamuwalde bites and kills cabbie Juanita Jones and, after finding Tina’s purse, rests in his coffin to avoid the coming dawn. Back at the police station, Gordon discovers that Bobby’s autopsy report is missing and requests that his supervisor, Lt. Jack Peters, authorize another. That night, Gordon, Tina and Michelle are celebrating the latter’s birthday at the Ethiopia Club when Mamuwalde enters and returns Tina’s purse. After apologizing to the young woman, Mamuwalde explains that Tina’s resemblance to his deceased wife compelled him to follow her. Inexplicably attracted to the commanding gentleman in his eighteenth century cape and suit, Tina invites him to their table, despite club flirt Skillet’s opinion that their new friend is “one strange dude.” When club photographer Nancy snaps a photograph of him and Tina, Mamuwalde, knowing that a vampire's image cannot be reproduced on film, abruptly leaves. Following Nancy as she leaves the club, Mamuwalde enters her home darkroom and kills her with one bite, then destroys the print she has just made of Tina hugging his absent figure. Meanwhile, Gordon begins to suspect that the string of killings might be the work of a vampire. After reading about the undead and learning that Bobby’s body is missing, Gordon requests that the police exhume Billy’s body for an autopsy, but his request is denied. Gordon and Michelle then spend the night digging up Billy’s grave. When the shovel hits the lid of the coffin, Billy’s dead body erupts from the coffin and hungrily attacks Gordon for his blood, but Gordon beats him back with his shovel, then stabs him in the heart with a wooden stake. Realizing that he must convince Peters of the strange and unbelievable vampire epidemic, Gordon calls coroner’s assistant Sam to pull Juanita’s body out of the deep freeze to thaw. Knowing she will awaken thirsty for blood, Gordon orders Sam to lock the body in the viewing room, but the distracted man forgets. Meanwhile, at Tina’s apartment, Mamuwalde finally reveals his real identity and what happened to him 300 years ago. Far from fearful, Tina is drawn closer to Mamuwalde and, although unwilling to become a vampire herself, makes love to him. Just before dawn, Gordon enters the morgue, accompanied by Peters, to find a voracious Juanita invigorated by Sam’s blood. Using a silver cross, Gordon forces Juanita to the window, where the rising sun instantly kills the vampire. Gordon and Peter then put out an all points bulletin for Bobby and Billy, hoping to stop the number of vampires from multiplying. Later that night, at the club, when Michelle and Gordon question him about vampires, Mamuwalde shares his reverence for the occult and then leaves abruptly with Tina. Learning that Nancy is missing, Gordon goes to her apartment and finds the negative of the photograph Mamuwalde had destroyed earlier. Their suspicions about Mamuwalde’s real identity confirmed, Gordon and Michelle rush to Tina’s apartment, where Gordon punches Mamuwalde, who narrowly escapes police capture. Deducing that the warehouse where the first murders took place is the vampires’ daytime resting place, Gordon and Peters break in with several police officers, but are soon surrounded by many vampires, all lusting for blood. After officer Johnson is bitten and instantly turns into one of the creatures, Gordon and Peters set the building on fire, burning the vampires, then stab Johnson with a wooden stake to end his tortured life. Turning to flee, Gordon and Peters are confronted by Mamuwalde, who tells them that Tina’s life means more to him than his own, then turns into a bat and flies away. Although Tina’s building is surrounded by police for protection, Mamuwalde uses his telepathic powers to lure her out of the apartment and guide her to a huge underground factory complex. Having spotted Tina, Gordon, Peters and the police rush into the maze of hallways, but Mamuwalde begins to kill the officers one by one. When one officer mistakenly shoots and mortally wounds Tina, the heartbroken and vengeful Mamuwalde yells into the bowels of the factory that no one will escape alive. Knowing he must save her from mortal death, Mamuwalde plunges his teeth into Tina’s neck, transforming her into a vampire. Only minutes later, Gordon and Peters find Mamuwalde’s coffin and, assuming that they have found the creature, plunge a stake into the body inside, only to discover Tina, who screeches wildly and dies. Unable to endure life without Tina, Mamuwalde walks up the stairwell into the blinding daylight, where he instantly dies, his body turning into a rotting skeleton.