Renfield (Dwight Frye), a British solicitor, travels through the Carpathian Mountains via stagecoach. The people in the stagecoach are fearful that the coach won’t reach the local inn before sundown. Arriving there safely before sundown, Renfield refuses to stay at the inn and asks the driver to take him to the Borgo Pass. The innkeeper and his wife seem to be afraid of Renfield’s destination, Castle Dracula, and warn him about vampires. The innkeeper's wife gives Renfield a crucifix for protection before he leaves for Borgo Pass, whence he is driven to the castle by Dracula's coach, which was awaiting him at Borgo Pass, with Dracula himself disguised as the driver. During the bumpy ride, Renfield leans out and starts to ask the driver to slow down, but is startled to see that the driver has disappeared, and a bat is leading the horses.
Renfield enters the castle welcomed by charming but odd nobleman Count Dracula (Béla Lugosi), who unbeknownst to Renfield, is a vampire. Renfield expresses concern about the strange disappearance of the coach driver and his luggage, but Dracula assures him that he has arranged to have his luggage delivered. They discuss Dracula's intention to lease Carfax Abbey in London, where he intends to travel the next day. Dracula then leaves and Renfield goes to his bedroom. Dracula hypnotizes Renfield into opening a window and then causes him to faint. A bat is seen at the window, which then morphs into Dracula. Dracula's three wives suddenly appear and start to move toward Renfield to attack him, but Dracula waves them away, and he attacks Renfield himself.
Aboard the schooner Vesta, bound for England, Renfield has now become a raving lunatic slave to Dracula, who is hidden in a coffin and gets out for feeding on the ship's crew. When the ship arrives in England, Renfield is discovered to be the only living person in it; the captain is lashed on the wheel and none of the ship’s crew is discovered. Renfield is sent to Dr. Seward’s sanatorium.
Some nights later at a London theatre, Dracula meets Dr. Seward (Herbert Bunston), who is with a group in a box seat area. Dr. Seward introduces his daughter Mina (Helen Chandler), her fiancé John Harker (David Manners), and the family friend Lucy Weston (Frances Dade). Lucy is fascinated by Count Dracula, and that night, after Lucy has a talk with Mina and falls asleep in bed, Dracula enters her room as a bat and feasts on her blood. She dies in an autopsy theatre the next day after a string of transfusions, and two tiny marks on her throat are discovered.
Several days later, it is seen that Renfield is obsessed with eating flies and spiders, devouring their lives also. Professor Van Helsing (Edward Van Sloan) analyzes Renfield's blood, discovering Renfield’s obsession. He starts talking about vampires, and that afternoon chats with Renfield, who begs Dr. Seward to send him away, because his nightly cries may disturb Mina’s dreams. When Dracula awakes and calls Renfield with wolf howling, Renfield is disturbed by Van Helsing showing him a branch of wolfbane. It stops wolves, as Van Helsing says, and also is used for vampire protection.Dracula visits Mina, asleep in her bedroom, and bites her, leaving neck marks similar to those on Lucy. The next morning, Mina tells of a dream in which she was visited by Dracula. Then, Dracula enters for a night's visit at the Sewards. Van Helsing and Harker notice that Dracula does not have a reflection in a mirror. When Van Helsing shows this "most amazing phenomenon" to Dracula, he reacts violently, smashes the mirror and leaves. Van Helsing deduces that Dracula is the vampire.
Meanwhile, Mina leaves her room and runs to Dracula in the garden, where he wraps his cape around her and attacks her; the next morning, she is found and awakened from unconsciousness. Newspapers report that a "mysterious, beautiful woman in white" has been luring children from the park with chocolate, and then biting them. Mina recognizes the beautiful lady as Lucy, who has risen as a vampire. Harker wants to take Mina to London for safety, but he is finally convinced to leave Mina with them. Van Helsing orders Nurse Briggs (Joan Standing) to take care of Mina when she is sleeping, and not to remove the wreath of wolfbane from around her neck.
Renfield again escapes from his cell and listens to the three men discussing vampires. Before Martin (Charles K. Gerrard), his attendant, arrives to take Renfield back to his cell, Renfield relates to Van Helsing, Harker and Seward how Dracula convinced Renfield to allow him to enter the sanitorium by promising him thousands of rats with blood and life in them.
Dracula enters the Seward parlour and talks with Van Helsing. Dracula states that because he has fused his blood with Mina's, she now belongs to him. Van Helsing swears revenge by sterilizing Carfax Abbey and finding the coffin where he sleeps; he will then thrust a stake through his heart. Dracula tries to hypnotize Van Helsing, almost succeeding, but Van Helsing shows a crucifix to the vampire and turns away.
Harker visits Mina on a terrace, and Mina speaks of how much she loves "nights and fogs". Harker notices Mina’s changes and says he likes them, not realizing that she is slowly transforming into a vampire. A bat (Dracula) flies above them and squeaks to Mina, to which she responds: "Yes? ... Yes? ... I will". Mina then tries to attack Harker. Fortunately, Van Helsing and Dr. Seward arrive just in time to save him. Mina confesses what Dracula has done to her, and tries to tell Harker that their love is finished.
Later that night, Dracula hypnotizes Nurse Briggs into removing the wolfbane wreath from Mina's neck and opening the French windows so he can enter her room. Van Helsing and Harker see Renfield, having just escaped from his cell, heading for Carfax Abbey. They see Dracula with Mina in the abbey. When Harker shouts to Mina, Dracula sees them, thinking Renfield had trailed them. He strangles Renfield and tosses him down a staircase, and is hunted by Van Helsing and Harker. Dracula is forced to sleep in his coffin, as sunrise has come, and is trapped. Van Helsing prepares a wooden stake while Harker searches for Mina. He finds her in a strange stasis. Dracula moans in pain when Van Helsing impales him, and Mina returns to normal. Harker leaves with her while Van Helsing stays. Church bells are heard, implying that they will be married.
Italiano
Renfield, un agente immobiliare, viene mandato in Transilvania per definire e concludere l'acquisto dell'abbazia di Carfax da parte di un certo conte Dracula. Questi, grazie ai suoi poteri mentali, soggioga Renfield e lo costringe a servirlo, portandolo alla pazzia.
Arrivati a Londra, Renfield viene rinchiuso in manicomio, mentre il conte transilvano fa la conoscenza dei suoi futuri vicini di casa, la quale figlia, Mina, sta per andare in sposa ad un collega di Renfield, Jonathan Harker. Dracula riesce a sedurre Mina e la sua amica d'infanzia Lucy, ma Harker, grazie all'aiuto dell'eminente professor Abraham Van Helsing, riesce a sconfiggere il conte, piantandogli un paletto nel cuore.