In a double-blind trial, 30 patients with suspected acute myocardial infarction with onset of symptoms within the previous 24 h were randomized to treatment with 10 mg nifedipine/placebo orally 4 times a day during hospitalization. All patients were given 15 mg metoprolol intravenously 20 min after the initial administration of nifedipine/placebo, and thereafter, 50 mg 4 times a day. The combined therapy resulted only in moderate changes in systolic blood pressure and heart rate compared with metoprolol alone. Three of the 15 patients in the nifedipine group versus 2 of the 15 in the placebo group were withdrawn because of hypotension and/or bradycardia. None was withdrawn because of congestive heart failure or A-V block. It is concluded that the combination of nifedipine and metoprolol seems to be a relatively well-tolerated combination in acute myocardial infarction.