The clinical efficacy of propranolol and metoprolol slow-release tablets (Durules) was compared in 20 patients with typical angina pectoris and concomitant hypertension. During a four-week run-in period all patients were given 80 mg propranolol b.i.d. in a single-blind fashion. Thereafter they were randomised in a double-blind fashion to treatment with either propranolol tablets, 80 mg b.i.d., or metoprolol Durules, 200 mg o.m. After four weeks, treatment was changed according to a cross-over design. The number of anginal attacks and nitroglycerin consumption were recorded by the patients in diary-cards. At the control visits, blood pressure was assessed in the supine and standing positions. No differences were found between the drugs as regards either antianginal or antihypertensive efficacy. Metoprolol Durules 200 mg o.m. are considered to be as effective as propranolol, 80 mg b.i.d. and may be preferred by some patients because of the simple dosage regimen.