Although Carmilla is a lesser known and far shorter Gothic vampire story than the generally-considered master work of that genre, Dracula, the latter is heavily influenced by Le Fanu's novella.
In the earliest manuscript of Dracula, dated 8 March 1890, the castle is set in Styria, although the setting was changed to Transylvania six days later. As with Dracula, critics have looked for the sources used in the writing of the text. Matthew Gibson proposes that Le Fanu used Dom Augustin Calmet's Dissertations sur les apparitions des anges, des demons et des esprits, et sur les revenants et vampires de Hongrie, de Boheme, de Moravie, et de Silesie, which was first anonymously translated into English in a single volume in 1759.

Le Fanu was an Irish writer of Gothic tales and mystery novels. He was the leading ghost-story writer of the nineteenth century and was central to the development of the genre in the Victorian era. Three of his best known works are Uncle Silas, "Carmilla" and The House by the Churchyard.