Objectives. To determine the prevalence of overweight and obesity according to the criteria of the WHO and CDC in adolescents from an urban district of Lima, Peru 2012. Materials and methods. This cross-sectional study included 1,743 school children of 12 to 17 years of age selected from ten public and private educational institutions, using a randomized and stratified sample of “conglomerados” (neighborhoods). In the selected schools, weight and height were measured. For the diagnosis of overweight and obesity, criteria from the WHO and CDC were used. For data analysis, descriptive and inferential statistics were performed. Results. According to the WHO criteria, the prevalence of overweight was 33.7% (95% CI 31.5-36.0) and obesity was 14.4% (95% CI 12.8-16.1). According to CDC criteria, the prevalence of overweight was 26.5% (95% CI 24.4-28.6) and obesity was 13.9% (95% CI 12.3-15.6). The prevalence of overweight and obesity was significantly higher in males aged 12 and 13 years old and private educational institutions (p<0.05). We found very good agreement between the WHO and CDC criteria for the diagnosis of overweight and obesity. Conclusions. A high prevalence of overweight and obesity was found, predominantly in male students between 12 and 13 years and private educational institutions. It is necessary to initiate intervention measures that can contribute to the prevention of chronic diseases in adulthood, secondary to obesity in adolescence.