Research into vascular dementia (VaD) has started relatively late. This is remarkable since there are more preventive and therapeutic options in VaD as compared to Alzheimer's disease. Lack of consensus with regard to diagnostic criteria, classifcation and terminology long hampered the progress of scientific research. Recently, consensus diagnostic criteria have been proposed, introducing the new elements of a causal relationship between stroke nad dementia and neuroimaging data. These proposals seem promising. The formerly often used Ischemic Score of Hachinski and coworkers still can be applied for exclusion of vascular factors in dementia. In the opinion of many clinicians, some clinical characteristics, e.g. depression, seem to favour a vascular aetiology rather than a neurodegenerative one. Empirical data show that on everage here may be small differences between different types of dementia, but in the individual patient these have relatively little value for the differentiation between VaD and AD. The need for investigations that evaluate the efficacy of preventive and therapeutic interventions is compelling.