The aim of this work was to compare the nutritional status of children from low and high socioeconomic levels. Weight, height, mid arm circumference and tricipital skinfold thickness were measured in 1,842 children of low and 2,770 of high socioeconomic status. Mean weight, height, and mid arm muscular circumference were higher in children of high socioeconomic status. Also, growth failure and overweight had a higher frequency among children of low socioeconomic status. Mean weight, height and mid arm circumference were higher in males of both groups. Among children of low socioeconomic status, height/age ratios were lower in men and weight/height ratios were higher in women. These differences were not observed in children of high socioeconomic level. We conclude that adverse environmental conditions, lower physical activity and indigenous ancestors may alter the nutritional status of children of low socioeconomic levels.