Perindopril is the newest angiotensin-converting enzyme inhibitor to be approved in the United States. It is indicated for the treatment of essential hypertension either alone or in combination with other antihypertensives, especially thiazide diuretics. Perindopril must be converted to perindoprilat, its active metabolite. The drug's prolonged duration of action allows for once daily administration. This article reviews clinical trials performed using perindopril alone and in combination to treat essential hypertension. The use of perindopril for congestive heart failure is reviewed. The influence of perindopril on arterial wall properties is discussed. Tolerability, drug interactions, and dosage and administration of the drug are reviewed.