To fulfill criteria for probable Alzheimer's disease (AD), patients must be free of cerebrovascular lesions that may explain the cognitive decline. These criteria probably lead to an underestimation of the links between risk factors for stroke and AD. However, the association between stroke and AD is probably more frequent than expected. Arterial hypertension is the most important risk factor for stroke. The aim of this study is to evaluate, from the literature, the possible relationship between blood pressure and AD. Cognitive performances are usually lower in patients with arterial hypertension. A longitudinal study revealed that patients with AD aged 79-85 are more likely to have had higher values of blood pressure 10 to 15 years earlier, and they usually have a spontaneous decline of blood pressure beginning 1 or 2 years before the onset of AD. The relationship between arterial hypertension and AD is probably due to the summation of Alzheimer pathology, white matter changes and cerebrovascular lesions. A possible consequence of these findings would be to prevent, or to postpone, AD by an early treatment of arterial hypertension. This is currently evaluated in drug trials.