Presently, the most prevalent nutritional problem of school age Chilean children is weight excess, specially on women, with a high percentage of growth retardation in both sexes. Secular tendency in Chile is to increase weight and growth, correlated with improvement of the economic situation of the country. We were interested in analyzing characteristics of weight and stature of school age Chilean children according to sex and geographic areas, and to determine the variations according to the reference standards used. 3282 school age children of basic education of both sexes were studied (1663 males and 1619 females), belonging to state schools of 3 areas of the country: Calama (989), Santiago (1361) and Temuco (932). Nutritional status was expressed as the percentage of adequation of weight to percentile 50 of WHO tables and National tables (Burrows-Muzzo). Results were expressed as average and distributed in < 90; 90-110; 110-120 and > 120% of adequation. Statural adequation was expressed as percentage of adequation of stature to percentile 50 of WHO and Nutritional tables, as average and distributed on < 95 ; 95-105 and > 105% of adequation. It was found that weight excess (> 120%) according to WHO was less in males than females (17.7 vs 24.6%) while growth failure did not differ per sex (33.3%). Weight excess was greater by WHO than National tables in males (17.7 vs 14.6%) and in females (24.6 vs 18.3%, respectively), while statural retardation (H/A < 95%) was greater by WHO tables than by National tables in males and females (33.6 vs 13.9 and 33.3 vs 15.1%, respectively). Weight excess by geographic area was less in males than in females in Calama (16.2 vs 20.5%), Santiago (20.0 vs 26.2%) and Temuco (16.0 vs 26.4%). Statural retardation was similar in males and females from Calama (30.6 vs 32.5), Santiago (29.0 vs 29.6) and Temuco (43.7 vs 39.6%). We conclude that WHO tables give in both sexes higher values of weight excess and statural retardation than National tables. This study demonstrated the high prevalence of weight excess (specially in females from Santiago) and growth retardation in both sexes, being higher in Temuco than in other areas. This information help orienting national programs directed to child health.