The inheritance of familial hyper‐alpha‐lipoproteinemia was investigated in 161 individuals in 11 black kindreds and 15 white kindreds. After age and sex adjustment, the distribution of high density lipoprotein‐cholesterol (C‐HDL) in the relatives of probands was examined for evidence of bimodality. In whites, bimodality appeared to be present, with one mode at about 46 mg/dl and the other at about 69 mg/dl. In blacks, there was little convincing evidence of bimodality. In the white kindreds, it appeared that one factor with a relatively large effect is causing the familial aggregation of high C‐HDL levels; this factor could be a m