Coronary heart disease (CHD) is the leading cause of mortality among people with diabetes. Although diabetes is more prevalent among blacks than among whites, little is known about CHD risk among black people with diabetes. We performed a case-control analysis to assess CHD mortality risk among people with diabetes. Coronary heart disease mortality cases were identified from the 1986 National Mortality Followback Survey, and controls were taken from behavioral risk factor surveys conducted in 35 states in 1988. In the young age groups (men younger than 45 years and women younger than 55), both white and black people with diabetes and no other CHD risk factors had about a thirteen-fold greater risk of CHD mortality compared to people without diabetes and with no other CHD risk factors. In the older age groups, diabetes was associated with a lower risk of CHD mortality among blacks (OR = 1.6) than among whites (OR = 2.5). With the exception of smoking in young people with diabetes, we found smoking, high blood pressure, and body mass to carry generally similar relative risks of CHD mortality in black people with diabetes as in white people with diabetes. Further study of other CHD risk factors is needed in black people with diabetes.