Although it has long been felt that dementia may be due to atherosclerosis, the concept has recently evolved to include multiple pathophysiological mechanisms related to deficiencies in cerebral blood supply. Epidemiological data has identified hypertension and stroke as the most potent risk factors for the development of vascular dementia (VaD). New diagnostic criteria have been proposed and new neuroimaging techniques have led to a better detection of cerebral vascular pathology. However, the differential diagnosis between Alzheimer's disease and VaD, the two most common causes of dementia, remains clinically challenging. Therapeutic interventions for VaD are limited, nevertheless several lines of evidence suggest a strong potential for preventive treatment through the control of vascular risk factors.