The Multiple Risk Factor Intervention Trial was a primary prevention trial to test the effect of multifactor intervention on coronary heart disease mortality in high-risk men who were randomly assigned to special intervention (n = 6428) or to their usual sources of health care (n = 6438). As previously reported, after 6 to 8 years of intervention, mortality from coronary heart disease and from all causes did not differ significantly between men assigned to special intervention and men assigned to their usual sources of health care. This report describes the mortality findings after 10.5 years (an average of 3.8 years after the end of intervention). Mortality rates were lower for men who received special intervention than for men who received their usual care by 10.6% for coronary heart disease and by 7.7% for all causes. Differences in mortality rates were substantially larger after the end of intervention than observed to that point. Differences in mortality rates after 10.5 years were primarily due to a 24% reduction in the death rate from acute myocardial infarction in men receiving special intervention compared with men receiving their usual care. As before, mortality differences between special intervention and usual care varied according to the presence of resting electrocardiographic abnormalities. These data suggest that multiple risk factor intervention confers a mortality benefit in middle-aged men over a period of about 10 years.