Although the value of treating all degrees of hypertension has been clearly established, a substantial percentage of patients fail to comply with drug therapy and thus do not receive the long-term benefits of blood pressure reduction. Antihypertensive drugs can have a negative impact on the patient's overall quality of life, as judged by their physical state, emotional well-being, cognitive acuity, and sexual and social functioning. These effects can be quite troubling to patients with a seemingly symptomless disease. In order to examine more closely the effects of different antihypertensive agents on quality of life, a double-blind, multicenter trial was conducted in which male patients were assigned to treatment with either methyldopa, propranolol or captopril for six months. Hydrochlorothiazide was added to the primary drug in patients whose blood pressure was not adequately controlled after eight weeks. Quality of life was evaluated using a battery of validated psychological assessment scales and indexes. Captopril was favored over methyldopa and propranolol on a number of the quality of life measures, including general well-being, physical symptoms, and sexual dysfunction. Addition of a diuretic negatively affected quality of life in all three primary drug groups, but captopril was still favored over the other primary drugs even when the effect of the diuretic was considered. The study demonstrated that quality of life is relevant and assessable and can be influenced by the choice of drug therapy. Greater attention by physicians to quality of life issues can hopefully improve patient compliance and extend the benefits of long-term antihypertensive therapy to more patients.