A growing proportion of the general population is being prescribed anti-hypertensive medications for the long-term treatment of essential hypertension. Untreated hypertensive individuals exhibit some neuropsychological performance decrements, and numerous researchers have sought to determine whether drug therapy for hypertension worsens, improves, or leaves unaltered objectively measured cognitive skills. These issues may be especially important in the elderly, among whom both high blood pressure and compromised cognitive function are common. In this review, we collate the findings of more than 50 clinical studies according to class of antihypertensive medication studied and domains of neuropsychological performance assessed. Special attention is given to investigations of elderly subjects, and a critical summary is provided.