The aim of the study was to examine the hypotensive efficacy and tolerance of bisoprolol in elderly patients, Sixty patients (40 <65 years and 20 >65 years) with mild-to-moderate essential hypertension (diastolic blood pressure (DBP) between 95 and 109 mm Hg) were included in the study. After a 2-week run-in period on placebo, patients began bisoprolol therapy (5 mg/d) for 12 weeks. After 4 weeks the dose was increased to 10 mg/d in those with a DBP greater than or equal to 95 mm Hg. Additionally, in 10 patients over 65 years old, 24-h ambulatory BP monitoring (ABPM) was performed, after placebo and after bisoprolol (5 mg) administration. The hypotensive efficacy of bisoprolol in the elderly and younger patients was similar. Before and after treatment the mean difference of systolic BP (SBP) was 19.6 +/- 12.5 mm Hg and DBP 9.6 +/- 6.2 mmHg in the younger patients and 16.1 +/- 13.6 mm Hg and 9.5 +/- 6.0 mm Hg in the elderly patients. Bisoprolol produced a similar reduction in heart rate (23.1% vs 17.1%) in the estimated groups, The tolerance of bisoprolol was good in both groups, There were no significant differences in adverse drug reactions between the groups.