BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a hereditary cerebral microangiopathy associated with mutations in the Notch 3 gene. The clinical phenotype is characterized by cerebral impairment even though typical microvascular changes are diffuse. OBJECTIVE: To assess peripheral neuropathy in patients with CADASIL. PATIENTS AND METHODS: We enrolled eleven CADASIL patients with variable phenotype including clinical signs of peripheral nerve involvement. In all patients electromyography and nerve conduction velocities were performed. Peripheral nerve biopsy was performed in three cases. RESULTS: We found sensory motor neuropathy in 7/11 patients. Nerve biopsy revealed axonal and demyelinated findings. CONCLUSION: Our findings suggest that peripheral neuropathy may be part of the CADASIL phenotype.