In the spring of 1992 schoolchildren (679 boys and 661 girls) aged 6-12 years in a school in central Hanoi, Vietnam were enrolled for a medical examination including measurements of height and weight. Most of them were measured a second time almost exactly 1 year after the first measurement. Thus, values for height, weight, and body mass index (BMI), and their yearly increments were obtained for the ages 7-11 years. When these heights and weights were compared with those for children from Bangkok, Tokyo and Sweden, the Hanoi values were very close to the Bangkok ones. There were overall no significant differences in height, weight, and BMI between children whose parents were of different occupational and educational groups, except for girls whose mothers were workers/farmers, who were shorter (P