In 1977, the first reports were published of a hereditary disorder characterized by recurrent subcortical ischemic strokes and stepwise progression of neurologic deficits leading to dementia, pseudobulbar palsy, and severe disability (Sourander and Walinder 1977; Stevens et al 1977). Since then, the disorder has been referred to by several names, including "hereditary multi-infarct dementia" and "familial sclerosing vasculopathy" (Colmant 1980; Sonniner and Savontaus 1987). In the 1990s, the disorder came to be known formally by the awkward, but clinically accurate designation "cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy." It was immediately recognized that a more user-friendly working nomenclature was needed, and the acronym "CADASIL" emerged (Tournier-Lasserve et al 1993; Sabbadini et al 1995). The acronym is now more commonly used (and probably more commonly recognized) than the full name of the disorder. Therefore, as is true of virtually all manuscripts, book chapters, and discussions of this subject, this review will use the acronym throughout its text.