The brain is an early target for organ damage due to high blood pressure. Hypertension is the major modifiable risk factor for stroke and small vessel disease. It has been suggested that cerebral microvascular disease contributes to vascular cognitive impairment. The mechanisms underlying hypertension-related cognitive changes are complex and not yet fully understood. Both high and, especially in the elderly, low blood pressure (BP) have been linked to cognitive decline and dementia. There is some evidence that antihypertensive drug treatment could play a role in the prevention of cognitive impairment through BP control. The BP levels that should be targeted to achieve optimal perfusion while preventing cognitive decline are still under debate.