Beta blockers are often considered to be less effective for blood pressure control in elderly patients with essential hypertension than calcium antagonists. We therefore compared the efficacy and tolerability of the new beta blocker bisoprolol with those of nifedipine. Fifty-nine patients over 60 years of age with essential hypertension (supine diastolic blood pressure, DBP: 95-115 mmHg) took part in a randomized double-blind study. After 14 days on placebo the patients received either 10 mg bisoprolol o.d. or 20 mg nifedipine SR b.i.d. for 4 weeks. The doses were doubled in patients whose DBP remained greater than 90 mmHg, for a further 4 week period. Blood pressure was measured about 24 hours after bisoprolol and about 12 hours after nifedipine administration. Fifty-six patients were available for efficacy analysis. After 4 weeks there was a distinct decrease of SBP and DBP in both groups (bisoprolol: -22 +/- 16; -15 +/- 9 mmHg; nifedipine: -24 +/- 17; -17 +/- 7 mmHg) with no significant difference between the treatments. DBP was normalized in 22/28 (79%) patients on bisoprolol and in 24/28 (86%) patients on nifedipine (bisoprolol vs nifedipine: NS). There were 7/29 bisoprolol and 14/30 nifedipine patients who experienced at least one side-effect. Overall the tolerability of bisoprolol was considered to be better than that of nifedipine (P = 0.043). In conclusion, bisoprolol 10-20 mg o.d. proved to be as equally effective as nifedipine SR 20-40 mg b.i.d. for the treatment of essential hypertension in the elderly.