The effect of verapamil on death and major events (i.e., death or reinfarction) after an acute myocardial infarction was studied in a double-blind, randomized, placebo-controlled multicenter trial. Eight hundred seventy-eight patients started treatment with verapamil, 360 mg/day, and 897 patients with placebo. Treatment started in the second week after admission and continued for up to 18 months (mean 16 months). Ninety-five deaths and 146 major events occurred in the verapamil group and 119 deaths and 180 major events in the placebo group. The 18-month mortality rates were 11.1 and 13.8% (p = 0.11, hazard ratio, 0.80; 95% confidence limits, 0.61 to 1.05), and major event rates 18.0 and 21.6% (p = 0.03, hazard ratio, 0.80; 95% confidence limits, 0.64 to 0.99) in the verapamil and placebo groups, respectively. In patients without heart failure in the coronary care unit the mortality rates were 7.7% in the verapamil group and 11.8% in the placebo group (p = 0.02, hazard ratio, 0.64; 95% confidence limits, 0.44 to 0.94), and major event rates 14.6 and 19.7% (p = 0.01, hazard ratio 0.70; 95% confidence limits (0.52 to 0.93). In patients with heart failure the mortality rates were 17.9 and 17.5% (p = 0.79, hazard ratio, 1.05; 95% confidence limits, 0.72 to 1.54), and major event rates 24.9 and 24.9% (p = 1.0, hazard ratio 0.98; 95% confidence limits 0.72 to 1.39). Long-term treatment with verapamil after an acute myocardial infarction caused a significant reduction in major events, and the positive effect was found in patients without heart failure.