This study investigated (1) the nutritional status of urban American disadvantaged children, (2) the relationship of nutritional status to mental growth and development, (3) the relationship of physical maturation to the development of perceptual-motor factors of intelligence, and (4) if found, the effects of undernutrition on intellectual achievement and physical development. Subjects were 60 Detroit 5-year-olds, half of whom were disadvantaged. Sex and race were also controlled in the sample. Results showed few, if any, nutritional deficiencies. Negro children appeared slightly taller and heavier as a group when compared to the norms of Caucasian children measured over 3 decades ago. With the exception of a marked positive correlation between height and psychological performance test scores in boys, no relationship between physical measures and intelligence test scores was found. It was felt that if a nutritional deficiency existed in the children, it was at a level that permitted physiological adaptation by the child so that growth was not appreciably affected. Re-examination of the data is suggested, since results imply that other factors exert a more profound influence on mental development in the children studied than do nutritional and physical growth variables, per se. (Author/DR)