Background <p>There is a lack of information regarding body composition (BC) measurements by Dual X-ray emission absorptiometry (DXA) in pediatric age group, mostly normative data to allow comparison among different populations and establish cut-off values. Aging itself, several chronic diseases and use of concomitant medications are associated with changes in BC, which can lead to cardiovascular events, metabolic complications, increased risk of functional loss, falls and death. Our purpose of the study is to establish BC normative data by DXA in healthy Brazilian children and adolescents.</p> Methods <p>Healthy, eutrophic/overweight children and adolescents aged between 5 and 19 years were included. Medical conditions that could interfere with bone mass or BC were excluded. Participants underwent a clinical interview including details about food intake, sun exposure and physical activity. In addition, anthropometric data, pubertal stage analysis, and lumbar spine and whole body DXA measurements using Hologic QDR 4500 were performed in all participants. Individuals were divided into 4 groups: female and male with two age intervals each (between 5 and 9 years and between 10 and 19 years). BC parameters were bone mineral density (BMD), bone mineral content (BMC), total lean mass (TLM), appendicular lean mass (ALM), appendicular lean mass index (ALMI), fat mass (FM), fat mass index (FMI) and android to gynoid fat ratio (A/G) to obtain normative data according to age and gender.</p> Results <p>A total of 349 healthy volunteers were eligible and enrolled for the study. Females had significantly higher values ​​of fat mass values ​​than males. All BC measurements were significantly higher in pubescent than prepubescent girls and boys.</p> Conclusion <p>Our data provided BC normative data for healthy male and female Brazilian children and adolescents.</p> Clinical trial number <p>Not applicable.</p>