Background: Resistin is an adipokine secreted in adipose tissue that may be associated with the metabolic and endocrine disorders of obesity. Aim: To assess the association between serum resistin levels and body composition variables, in children and adolescents. Material and methods: Cross-sectional assessment of 302 subjects, aged 10-16 years. According to body mass index, 124 were classified as eutrophic and 178 as obese. A clinical examination and pubertal assessment were performed. Body weight, height, waist and arm circumferences were measured. Serum resistin levels were measured using an immunoenzymatic assay. Results: Male obese children had significantly higher resistin levels than their eutrophic counterparts. Eutrophic women had higher levels than eutrophic males. No significant association between resistin and pubertal status was observed. In the whole sample and among obese subjects, resistin levels correlated with body mass index, tricipital skinfold, arm circumference, arm fat area and fat mass. Conclusions: There is a significant association between resistin levels and body composition variables, particularly indicators of fat accretion.Background: Resistin is an adipokine secreted in adipose tissue that may be associated with the metabolic and endocrine disorders of obesity. Aim: To assess the association between serum resistin levels and body composition variables, in children and adolescents. Material and methods: Cross-sectional assessment of 302 subjects, aged 10-16 years. According to body mass index, 124 were classified as eutrophic and 178 as obese. A clinical examination and pubertal assessment were performed. Body weight, height, waist and arm circumferences were measured. Serum resistin levels were measured using an immunoenzymatic assay. Results: Male obese children had significantly higher resistin levels than their eutrophic counterparts. Eutrophic women had higher levels than eutrophic males. No significant association between resistin and pubertal status was observed. In the whole sample and among obese subjects, resistin levels correlated with body mass index, tricipital skinfold, arm circumference, arm fat area and fat mass. Conclusions: There is a significant association between resistin levels and body composition variables, particularly indicators of fat accretion.