Japanese-American men have higher rates of non-insulin-dependent diabetes mellitus and coronary heart disease than same-aged men in Japan. Associations of educational attainment with either non-insulin-dependent diabetes mellitus or coronary heart disease were examined in a sample of 229 second-generation Japanese-American men (aged 45 to 74 years) living in King County, Washington (1984 through 1985). Men with a terminal school education showed higher frequencies of both disease compared to men with any college education and to men with high school educations. Occupation, income, diet, physical activity, weight, insulin, lipids, and lipoproteins were examined to determine whether they could account for the observed associations of educational attainment with disease. Logistic regression analysis indicates that the association of educational attainment with risk of coronary heart disease is explained, in part, by the larger average body mass index, higher total and VLDL triglyceride, and lower HDL and HDL-2 cholesterol observed in men with technical school educations compared to the other men. The association of educational attainment with risk of non-insulin-dependent diabetes is not explained by any of the factors examined. The findings suggest that attainment of a college education ameliorates some of the negative effects of westernization on the health of Japanese-American men.