The results from the Beta-Blocker Heart Attack Trial for patients ages 60-69 years indicate a significant beneficial effect of propranolol and an overall reduction in mortality of 33%. This beneficial effect appears to begin early and continues through 3 years of follow-up. Examination of patient complaints and medical reasons for withdrawing study medication indicates that side effects resulting from propranolol use were infrequent in both the younger and older age groups, and there were no major differences between the two groups. Given these results, and considering the large number of hospital-diagnosed myocardial infarctions that occur each year in persons older than 60 years of age, it appears that the use of propranolol, where not contraindicated, could delay mortality in a substantial number of older postinfarction patients.