Dementia is a growing problem of modern society causing significant percentage of morbidity and mortality in elderly people. Two major causes of dementia are vascular diseases and Alzheimer's disease. Recently it has been suggested that vascular dementia and Alzheimer's dementia might overlap in many aspects. Also it was suggested that vascular risk factors could have a role in Alzheimer's dementia onset and progression. Hypertension is one of the most significant risk factors for vascular diseases. The aim of study was to evaluate the role of hypertension in patients with Alzheimer's dementia (AD) and vascular dementia (VaD). Sixty-six patients with dementia were enrolled in this study. AD was diagnosed in 43 and VD in 23 patients. Hypertension was diagnosed if a patient had values higher than 130/85 on two successive measurements during different days, or if a patient was taking antihypertensive medication. In a group of 43 AD there was 24 patients with hypertension, and 19 patients were normotensive. In a group of 23 VaD patients there were 16 patients with hypertension and 7 patients were normotensive. Higher proportion of VaD patients had hypertension compared with AD group. However, hypertension was also present in significant proportion of AD patients. It is well known that VaD is associated with hypertension as on of the most prominent vascular risk factors. Data from this study show that in patients with AD there is also significant proportion of hypertension, supporting the idea that hypertension could also have some role in etiology, onset and progression of AD, as it has on pathogenesis of VaD.