Forty outpatients (11 men and 29 women) aged between 65 and 85 years (mean age of 68 years) with mild to moderate hypertension [mean systolic/diastolic blood pressure (SBP/DBP) after 2 weeks on placebo of 175/102 mm Hg] were included in a randomized, double-blind, parallel-group study to compare the efficacy and tolerance of 10 mg of bisoprolol once daily (o.d., n = 20) and 20 mg of nifedipine sustained release (SR) b.i.d. (n = 20) during 4 weeks of treatment. SBP and DBP were significantly reduced compared to baseline with both treatments. There was no significant difference in efficacy between the two treatments after 2 and 4 weeks. After 2 weeks, the number of patients with normalized DBP (< or =90 mm Hg) was higher with bisoprolol than with nifedipine, this difference no longer being present after 4 weeks. Resting heart rate was significantly reduced with bisoprolol from 78+/-8 to 68+/-9 beats/min after 4 weeks, but there was no change in heart rate with nifedipine. Adverse events were reported by 6 patients on bisoprolol (20 events) and 12 patients on nifedipine (51 events) and the overall tolerance of bisoprolol was considered to be significantly better than that of nifedipine. Because bisoprolol is equally effective when administered once daily in comparison with nifedipine SR, which has to be given twice daily, and since bisoprolol exhibits a better tolerance, this beta-blocker appears to be a useful drug of first choice for the treatment of elderly hypertensive patients.