Sometime in the late nineteenth century, Jonathan Harker, a young English lawyer, is traveling to the Castle Dracula, which is located in Transylvania, in order to finalize a transfer of real estate in England to Count Dracula. Harker becomes extremely nervous when all of the local peasants react in fear after they hear of his destination; nevertheless, he continues on to the castle until he meets an emissary of the Count in the Borgo Pass. The mysterious coach driver continues on to the castle, arriving in pitch darkness, to the accompaniment of howling wolves.
Even though his accomodations are comfortable, Harker finds Count Dracula to be a pale, gaunt, thin man, rather strange, and Harker is mortified when, after accidentally cutting himself shaving, the Count lunges at Harker's throat in "demoniac fury." Harker soon finds himself imprisoned within the castle and assailed by three seductive female vampires, whom he can barely stave off. Harker also discovers the Count's secret — that is, the Count survives by drinking the blood of human beings — and, now, he is intent on killing Harker. The Count escapes Jonathan's attempt to kill him, and he swiftly leaves the castle with fifty boxes of earth, bound for England. The last we hear of Jonathan Harker, he is weak and sick, left alone with no visible means of escape from the castle.
The novel then shifts to England, where Harker's fiancée, Mina Murray, is visiting her friend Lucy Westenra, who has accepted the marriage proposal of Arthur Holmwood, while rejecting the proposals of Dr. John Seward, head of a lunatic asylum, and Quincey Morris, an American from Texas, currently visiting Holmwood. Mina's two main concerns are that Lucy has taken up her old habit of sleepwalking, and that it is a long time since she has heard from her own fiancé, Jonathan.
One night while the two women are out walking, they witness the approach of a strange ship. When the ship is wrecked on the beach, the only creature which survives is a huge dog, which quickly disappears. We soon discover that the wrecked ship is carrying fifty boxes of earth from the Castle Dracula.
Soon after the shipwreck, late one night, Mina discovers that Lucy is sleepwalking again. In her search, Mina discovers Lucy on the ladies' favorite seat, near the graveyard overlooking the town. Mina is shocked to see hovering over Lucy a tall, thin, black shape, but when she arrives at Lucy's side the shape has disappeared. When awakened, Lucy remembers nothing of what has happened, except that she is chilled. In wrapping Lucy against the cold, Mina assumes that she inadvertently pricked Lucy with a pin, for she sees two tiny red marks on Lucy's neck. On later, successive nights, Lucy is often found standing at the women's bedroom window; next to her is a creature which appears to be a large bird, but it is, in fact, a bat. Lucy's health declines over the next few weeks, and because of this Mina refuses to tell Lucy about Lucy's mother's sickness. Meanwhile, Dr. Seward, Lucy's former suitor, is unable to ascertain the cause of Lucy's decline.
Soon, Mina hears from Jonathan, and so she leaves Lucy and goes to nurse him. Almost immediately, Lucy's condition deteriorates, and Dr. Seward finds it necessary to wire for his old friend and mentor, Dr. Abraham Van Helsing, who offers another medical opinion. Van Helsing is particularly disturbed by the two tiny spots on Lucy's throat and her apparent but unexplainable loss of blood since there are no signs of hemorrhage.
It becomes necessary to give Lucy numerous blood transfusions, and after each one she improves significantly, only to deteriorate quickly in the next couple of days. Van Helsing finally deems it necessary to drape Lucy's room, as well as her neck, with garlic, a technique, we learn later, which is used to ward off vampires. Eventually, however, the vampire manages to evade the spells against him, and he attacks Lucy again. One significant night, an escaped wolf is used to smash the window of Lucy's room. The wolf's attack so frightens Lucy's mother that she dies of shock, and Lucy, left helpless, is again attacked by the vampire.
Van Helsing, knowing that Lucy is near death, summons her fiancé, Arthur Holmwood, to her side. Holmwood himself comes from the deathbed of his father. As Holmwood bends to kiss Lucy goodbye, Lucy, whose canine teeth have become strangely lengthened, attempts to attack Arthur. As Van Helsing throws Arthur back from her, Lucy dies.
After Lucy's death, the papers report the strange appearance of a person whom the village children label as "the Bloofer Lady," a creature who has been attacking young children in the area. Van Helsing, shaken by the reports, summons Dr. Seward to attend him in an examination of Lucy's coffin. After Seward's initial shock, he agrees, albeit with reservations, to open Lucy's coffin.
In the meantime, Mina and Jonathan have been married, and they return to England. Mina has transcribed Jonathan's diary of his journey in Transylvania, and soon afterward Van Helsing reads it. Van Helsing then calls all of Lucy's ex-suitors together, and he explains to them his belief that Lucy has been bitten by a vampire and has become one herself. The only way to save her soul, he says, is to drive a wooden stake through her heart, cut off her head and stuff it with garlic. Eventually Van Helsing convinces them of the truth of his claims, and the "service" is performed on Lucy.
Now the protagonists begin a search for the Count and also for the fifty boxes of earth which he brought with him to England; these six people — Jonathan, Mina, Dr. Seward, Van Helsing, Holmwood, and Quincey Morris — vow to confront the vampire. Soon after the search begins, Van Helsing realizes that a dreadful change is taking place in Mina. One horrific night, Van Helsing and Seward break into Mina's room, find Jonathan unconscious, and Mina being forced to suck blood from a deep slash across Dracula's chest. In a twinkling, Dracula disappears.
They finally discover and destroy all of the fifty boxes except one, which they learn has been sent by ship back to Dracula's castle. Using various methods, including the hypnosis of Mina, they follow Dracula all the way to the Borgo Pass in Transylvania, where they find the last remaining box being transported to Castle Dracula by a group of gypsies. They overcome the gypsies, throw the box to the ground, tear open its lid, and discover the body of the Count. With a huge thrust, Jonathan cuts off the vampire's head, while Morris drives his knife into the Count's heart. The Count himself crumbles into dust, and Quincey Morris, having been wounded by the gypsies in an attempt to retrieve the box, dies of a mortal wound, and so the novel ends.