We conducted a multicenter randomized double-blind clinical trial among 626 men with mild to moderate hypertension to determine the effects of captopril, methyldopa, and propranolol on their quality of life. Hydrochlorothiazide was added if needed to control blood pressure. After a 24-week treatment period, all three groups had similar blood-pressure control, although fewer patients taking propranolol required hydrochlorothiazide. Patients taking captopril alone or in combination with a diuretic were least likely to withdraw from treatment because of adverse effects (8 percent vs. 20 percent for methyldopa and 13 percent for propranolol). The treatment groups were similar in scores for sleep dysfunction, visual memory, and social participation. However, patients taking captopril, as compared with patients taking methyldopa, scored significantly higher (P less than 0.05 to less than 0.01) on measures of general well-being, had fewer side effects, and had better scores for work performance, visual-motor functioning, and measures of life satisfaction. Patients taking propranolol also reported better work performance than patients taking methyldopa. Patients taking captopril reported fewer side effects and less sexual dysfunction than those taking propranolol and had greater improvement (P less than 0.05 to less than 0.01) on measures of general well-being. Our findings show that antihypertensive agents have different effects on the quality of life and that these can be meaningfully assessed with available psychosocial measures.