Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary form of small vessel disease in which the pons may show lacunar infarcts and leukoaraiosis. Acute pure vestibular syndrome may be due to caudal pontine lesions and is probably underestimated. We describe a case of CADASIL with acute vestibular syndrome mimicking peripheral vestibulopathy, and evidence of focal infarction in the ponto-medullary junction at gadolinium-enhanced MRI including diffusion-weighted imaging, involving the area of the right vestibular nucleus and root entry zone of the ipsilateral vestibular nerve bundle. In CADASIL, both focal brainstem lesions and leukoaraiosis may parallel supratentorial white matter changes and may be related to poor outcome. Their actual extent should be evaluated in longitudinal studies that might predict clinical outcome and progression of disability.