Background: Obesity in children/adolescents is a major public health problem worldwide. In Brazil there is great variability in published data on the prevalence of obesity among children/adolescents. Aims: To show a systematic review with meta-analysis of cross-sectional studies, conducted in Brazil between 2008 and 2014. Methods: A systematic review and meta-analysis was conducted the outcome of which was obesity (Body Mass Index ≥ 95th percentile for sex/age). A graphical presentation was done separately (Forest plot) for the results. Global and dichotomous outcomes were presented by employing, respectively the gross rates of prevalence and prevalence ratio (PR) and its confidence intervals at 95% (95% CI). The degree of heterogeneity was calculated employing the Q Cochran, while the I² test was used to describe the variation between studies. Results: Twenty-one studies with a sample of 18,463 children/adolescents were included; the overall prevalence of obesity was 14.1%. Among boys it was 16.1% and in girls it was 14.95%. There was no difference in obesity prevalence between sexes (PR 1.06; 95%CI: 0.81 to 1.40; p>0.05). Conclusions: The prevalence of obesity among children and adolescents in Brazil is high and urgently needs measures to prevent consequences associated with the disease, as well as measures to reduce the impact, in the short term, the overweight and childhood obesity.