Vittorio di Raniari was a sixteen year old nobleman living with his family in Tuscany, Italy. In 1450, his family is murdered by a coven of powerful and ancient vampires. Vittorio would have also been killed, if it was not for the vampire Ursula, who felt Vittorio was too beautiful to destroy. Vittorio takes care of his family's burial and vows to avenge their deaths, as his siblings severed heads strike deep into his soul. Gathering up all the family riches he can find, Vittorio flees toward Florence at daylight to escape the vampires.
On his way to Florence Vittorio arrives at a village where everyone is young and healthy; there are no beggars in the street, no sick, no elderly and no dying. Feeling someone stalking him, Vittorio stops at an inn to rest. Unbeknownst to him, Ursula is behind his bedroom window.
Ursula lures Vittorio to the coven lair, which is an old castle. In its garden he sees the elderly and sick that were absent from the village; the villagers made a pact that the vampires could have any of their weak if they would leave the rest of them alone. Vittorio witnesses a feast where some of these people are sacrificed for the vampires to feed on. Vittorio refuses the Dark Gift offered to him by the coven leader. They think about killing him, but thanks to Ursula, merely leave him alone in a village.
In the doorway of an inn, Vittorio sees two angels, Ramiel and Setheus, arguing. They are the guardian angels of his idol, Fra Fillipo Lippi. With their help and the help of a powerful angel named Mastema, Vittorio plots to kill the vampires who killed his family and who are now killing thousands of innocents.
During the daytime, Vittorio sneaks into the coven lair and beheads the sleeping coven members. He throws the heads out into the sunlight where they wither and die. Yet when it comes time to behead Ursula, despite the angels' urging Vittorio can not bring himself to kill the vampire who saved his life twice. Instead, he frees Ursula in hopes of saving her soul. Ursula tricks Vittorio into becoming a vampire and a taste for blood conquers everything he knows.
The last chapter of Vittorio the Vampire concerns Vittorio's life as a vampire. He and Ursula live as murderous thieves, killing innocents and robbing victims until their appetites are satisfied. The two become lovers and stayed with each other for over 500 years. He is one of the 17 vampires to survive Akasha's purge, although it is not clear whether Ursula has.
As a vampire, Vittorio can still see angels and souls, which appear inside a person as a blinding ball of white light. Mastema the angel tells Vittorio that whenever he kills a victim he witnesses the extinguishing of their soul.
"I was sixteen years old when I died. I have good height, thick brown hair down to the shoulders, hazel eyes that are far too vulnerable to behold, giving me the appearance of an androgyne in a way, and a desirable narrow nose with unremarkable nostrils, and a medium-sized mouth which is neither voluptuous nor stingy. A beautiful boy for the time. I wouldn't be alive now if I hadn't been."
"I don't have a childish face, but I have an almost angelic one. My eyebrows are strong, dark, high enough over my eyes to allow them entirely too much luster. My forehead would be a little too high if it wasn't so straight, and if I didn't have so much thick brown hair, making as it does a curly, wavy frame for the whole picture. My chin is slightly too strong, too squared off for the rest. I have a dimple in it."