In males, the incidence rate of coronary heart disease (CHD) in white noncigarette smokers was 52.7/1,000 and among blacks, 9.8/1,000; among white cigarette smokers the rate was 101/1,000 but in blacks only 32.5/1,000. The incidence rate of CHD in the leanest whites was 95.5/1,000, among the leanest blacks, 24.1/1,000; however, in the most obese whites the rate was 137/1,000 and among the blacks, 53.6/1,000. When comparing white smokers with nonsmokers in the leanest and most obese tertiles, smokers run a substantial risk of developing CHD, increasing with increase in overweight (80, 90, and 150/1,000, respectively). The risk of nonsmokers developing CHD does not increase from the leanest to the moderately overweight and the most obese group, (51, 30, and 64/1,000, respectively). Therefore, obesity in white males seems to enhance the risk of CHD among cigarette smokers but not among nonsmokers.