Dementia with Lewy bodies is a generic term which was proposed at the first International Workshop on Lewy Body Dementia (Newcastle upon Tyne, 1995). It is an all encompassing term that includes various types of disorder such as diffuse Lewy body disease, senile dementia of Lewy body type, and Lewy body variant of Alzheimer's disease. Epidemiological, clinical, neuropathological, biochemical, molecular biological, and therapeutic contributions to the understanding of dementia with Lewy bodies are reviewed.