The high-density lipoprotein cholesterol and high-density lipoprotein subfraction (HDL2 and HDL3) concentrations were examined in 170 young black adults. The women examined had significantly higher total high-density lipoprotein cholesterol concentrations than the men, i.e., 57.0 mg/dl vs 51.2 mg/dl, P less than 0.002. The increased high-density lipoprotein cholesterol among women represented a significant increase in both HDL2 and HDL3 cholesterol concentrations. The sex differential could not be explained by body mass index, alcohol consumption, or physical activity. The determinants of high-density lipoprotein cholesterol for men appeared to be different than those for women.