Obesity in school-aged children has reached epidemic levels, which is considered a chronic disease. Researchers have been on alert, given the rising prevalence of obesity in the last few decades. The objective of this study is to evaluate the relation between body weight and abdominal circumference as a predictor for nutritional status in school students from 7 to 12 years of age in the municipality of Cacoal, RO, Brazil. The current study is of a descriptive nature, with cross-sectional and quantitative analysis. The study sample had 482 school students, of both genders, 230 male ones and 252 female ones, divided into school students from the urban and teaching rural teaching areas. Body Mass Index (BMI), abdominal circumference, and body weight were the variants analyzed. Reading with general comprehension strategies. It was possible to notice that 13% of the school students from the rural area were obese. On the other hand, 25% of the school students from the urban area, including both genders, were obese. There was a significant relation in body weight variant versus abdominal circumference in both genders, in the two areas studied. The body weight variant showed a significant relation with abdominal circumference and with body weight index in both genders.