This study was conducted to obtain an accurate assessment of the nutritional status of the children in the Cusco, Peru Health District. It is a sample survey of anthropometric measures for 3,383 children under the age of 10 yr. The results showed a significant decline in nutritional status with age (96.88% normal range at ages 1-3 mo to only 37.43% normal at ages 12-24 mo) followed by a gradual improvement in the children above 2 yr (approximately 50% normal). The deficits at the older ages were principally due to low weights-for-age. Nutritional status was also dependent on sex, village altitude, remoteness, and population size (p less than 0.005). Of these, only sex interacted with age. The girls did significantly better at some ages and the boys better, but not significantly so, at other ages.