Cancer mortality in a higher-income black population in New York State. Comparison with rates in the United States as a whole. In the 1980 Census the median family income among blacks in Suffolk County, New York (i.e., $19,604) was much higher than that for American blacks as a whole (i.e., $12,618) and 94.1% of that for American whites (i.e., $20,840), but the proportion below the poverty level was still higher for Suffolk County blacks than for American whites. Observed numbers of deaths from 1979 to 1985 for total cancers and most cancer sites in Suffolk County black men and women were not lower than expected on the basis of age-specific and gender-specific death rates for blacks in the US. Although numbers of deaths from cervical cancer and prostate cancer were slightly lower than expected in Suffolk County blacks versus American blacks, these numbers were still significantly greater than expected on the basis of death rates among American whites. Age-specific death rates for age groups 25 to 44 years to 55 to 64 years tended to be lower in Suffolk County for lung cancers in black men but not for breast cancer in black women. Specific cancer sites, which differ in the direction of the association between incidence and socioeconomic status, age, and gender must be considered in comparisons of cancer mortality by race and socioeconomic level. Implications of the comparisons were discussed with regard to the goal of reducing racial differences in cancer death rates. 