Cognitive impairment and dementia are more and more common in the elderly. The first begins, it advances silently and it leads to dementia in few years. Arterial hypertension represents the most important cerebrovascular risk factor after age. In numerous studies an inverse relationship between blood pressure values and cognitive performance emerges: it is possible that arterial hypertension plays a role in the pathogenesis of cognitive decline. Even in asymptomatic subjects the magnetic resonance signs of cerebral damage accompany cognitive impairment development. Antihypertensive therapy influence on cognitive function represents a subject of actual interest. The most studied drugs are calcium antagonists and ACE-inhibitors; they seem to have a protective effect on cognitive impairment, with regard to diuretics and beta-blockers. It would be important to study hypertensive patients, above all young asymptomatic hypertensives, even about cognitive functions, to prevent and consider cognitive decline and effective organ damage.