Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is an inherited cerebrovascular disease due to mutations of the Notch3 gene at the chromosome locus 19p13. The clinical spectrum includes recurrent ischaemic episodes, cognitive deficits, migraine and psychiatric disorders. The histopathological hallmark of CADASIL is accumulation of electron dense granules (GOM) in the media of arterioles. MRI reveals extensive cerebral white matter lesions and subcortical infarcts. CADASIL was initially thought to be a rare disorder, but increasing numbers of families have been identified; therefore, it is likely that CADASIL is still largely underdiagnosed. Here we report an update on mutations of the Notch3 gene and some information on the pathogenesis of the disease.