A multicenter study was performed to assess the efficacy and the acceptability of indapamide in hypertensive patients previously untreated, or treated and unsatisfactorily controlled with either angiotensin-converting enzyme (ACE) inhibitor or β-blocking therapy. Four centers participated in the study, which included patients whose supine diastolic blood pressure was between 95 and 115 mm Hg with no treatment (group I, n = 40), those taking captopril (group II, n = 40) or those taking propranolol (group III, n = 40). After a 2-week single-blind placebo run-in period, patients received indapamide either alone (group I) or in combination with the previous therapy (groups II and III) for 4 months. Blood pressure, heart rate, weight, and clinical and biochemical acceptability were measured before and after 2 and 4 months of treatment. At the same time points, quality of life was determined using standardized questionnaires completed by the patient (20 items) and the physician (10 items) and a visual analog scale completed by the patient. In all groups, administration of indapamide induced a clinically and statistically significant reduction in both systolic and diastolic blood pressures in the supine position after 2 months. Indapamide atone controlled blood pressure in 82% of the patients previously untreated, and indapamide in combined therapy controlled blood pressure, respectively, in 67 and 85% of patients previously uncontrolled with ACE inhibitors or β blockers. In all groups, questionnaires on quality of life showed a progressive and significant improvement in general well-being. After 4 months of treatment, the percentage of improvement in the physician questionnaire was 77.1% in group I, 60.6% in group II and 71.4% in group III. Similar results were obtained with the patient questionnaire. Biochemical acceptability was characterized by the stability of all parameters, including sodium, potassium, glucose, creatinine, cholesterol and triglycerides and a slight increase in uric acid in all groups. These results confirm the satisfactory efficacy and acceptability of indapamide and its beneficial effects on quality of life when administered as a first-step therapy as well as in combination with β blockers or ACE inhibitors. © 1990.