This report contains national estimates based on findings from the Health Examination Survey in 1963-65 on height and weight measurements of children 6- to 11-years-old. A nationwide probability sample of 7,119 children was selected to represent the noninstitutionalized children (about 24 million) in this age group. Height was obtained in stocking feet with the head in the Frankfort Plane, subject standing erect but not manually elongated, and recorded by means of a polaroid camera mounted on the measuring rod. Weight was measured in standardized clothing on a self-recording scale. The present findings are compared with other findings, both in the past and in other countries. There has been a steady and very regular increase in both height and weight of children in the United States over the past 90 years. American children are among the largest in the world. American boys at age 6 are slightly taller and heavier than the girls, but, by age 11, the girls are larger. While heights for white and black boys in this age range are comparable, white boys are slightly heavier than black boys at every age. Black girls are taller and weigh slightly less than white girls until age 11. Height and weight as measures of growth of the developing human and the use of these findings as standards, both clinical and epidemiologic, is discussed. Three-fifths of this document consists of detailed tables. (Author/AJ)