Objective: The purpose of this study was to verify and set a standard for the Waist Circumference (WC) in children as a marker for abdominal obesity. Methods: The study involved 8 state schools in the city of Lins, state of São Paulo, Brazil. The population of the study comprised 882 children of both sexes, with ages ranging from 6 to 10. The following anthropometric variables were evaluated: BMI/A (body mass index in relation to age); W/A (weight in relation to age); the TSF (Tricipital Skinfold), and the WC. The curves used to determine the parameters evaluated here are for children and adolescents aged 2 to 20. Results: An analysis of the WC values in terms of pBMI/A, pTSF, and pW/A indicates that, in terms of the variables studied here, the WCs are the same for both sexes and it is reasonable to suggest that a correlation between the WC and the pBMI/A, pTSF and pW/A is a good parameter to diagnose the nutritional status of 6 to 10-year-old children, and that it can be used in clinical practice to aid the diagnosis of obesity and its correlation with the development of metabolic disorders. Conclusions: The results show that the WC is a valid parameter to diagnose the nutritional status of children between 6 and 10 years of age.