The Aspirin Myocardial Infarction Study (AMIS) was a multicenter, randomized, double-blind, placebo-controlled trial of 1.0 g of aspirin daily in men and women who had had a documented myocardial infarction. In the trial 4524 persons, ages 30-69 years, were recruited; 2267 were randomized to aspirin and 2257 to placebo. The major end point, total mortality, was 10.8% in the aspirin group and 9.7% in the placebo group. There was a nonsignificant trend indicating a lower incidence of nonfatal myocardial infarction in the aspirin group (6.3%) compared with the placebo group (8.1%). Symptoms suggestive of gastrointestinal irritation appeared in 23.7% of the aspirin group and in 14.9% of the placebo group. Based on these findings, routine use of aspirin after myocardial infarction is not recommended.