Between 1983-1985 somatic data were collected on 631 Black boys age nine years drawn from Ibo, Yoruba, and United States black ethnic groups living in urban and rural locations. On urban-rural subgroups, measures of body weight and skin-fat thickness were analyzed for central tendency and variability. On each of the ethnic-regional subgroups studied, the distribution of measures for each variable is, to some extent, skewed positively. United States urban Black boys exceed their Nigerian rural age-sex peers by 6.6 kg in body weight and by 0.6 cm and 0.7 cm in skin-fat thickness on the abdomen and at the back of the arm. The thirtieth percentile of the United States urban distributions for both skin-fat sites was higher than the seventieth percentile of the Nigerian rural and urban distributions.