The aim of this study was to assess the effects of long-term (9-month) treatment with isradipine, alone or combined with bopindolol, on blood pressure, left ventricular hypertrophy (LVH), and diastolic function. Thirty-five hypertensive patients with LVH and supine diastolic blood pressures (DBPs) greater than or equal to 100 and less than or equal to 120 mm Hg received increasing doses of isradipine (1.25, 2.5, and 5 mg twice daily); if blood pressure was not controlled, bopindolol (0.5-2 mg once daily) was added to the treatment. Clinical and laboratory investigations were carried out after placebo for baseline values, and after 5 and 9 months of isradipine treatment alone (n = 11) or combined with bopindolol (n = 24). At the end of the study, blood pressure was significantly decreased while heart rate did not change with isradipine alone, but decreased significantly after the addition of bopindolol. Although the DBP was normalized (less than or equal to 90 mm Hg) in 28 patients (80%), complete reversal of the left ventricular mass index (LVMI) was seen in only 7 patients (20%). The ratio of early to atrial filling did not change, but the deceleration time was significantly decreased after 9 months. No laboratory abnormalities or important side effects were observed. Although isradipine alone or combined with bopindolol was effective in controlling blood pressure and significantly reduced the LVMI after 5 months, improvement in diastolic function was seen only after 9 months of active treatment.