The various forms of dementia have traditionally been classified according to the criteria established by Kraepelin, Alzheimer and Biswanger and subsequently revised by Sir M. Roth. Vascular risk factors have always been considered to cause vascular dementia, while Alzheimer's disease was considered to be caused by other, poorly defined degenerative factors. However, in the last few years, a series of studies has revealed that classical vascular risk factors may also be involved in Alzheimer's disease. The present article reviews the role of insulin resistance, diabetes mellitus, hypertension, hypercholesterolemia, obesity, homocysteine levels, smoking, alcohol consumption and atrial fibrillation in Alzheimer's disease. Understanding of these associations may in future allow effective preventive measures to be taken.