Aim: To investigate the risk factors for metabolic syndrome (MS) in children and adolescents. Material and methods: Investigation conducted in the interval October 2010-June 2011 in 3103 school children aged 7-18 years. After body weight, height, waist circumference, and blood pressure were measured, 262 school children were found to be obese, of which 120 agreed to testing for defining the metabolic syndrome: triglycerides (TG), cholesterol, HDL and LDL cholesterol, blood glucose, insulinemia, OGTT (oral glucose tolerance test), SGOT, SGPT, urea, creatinine, and ESR. Results and discussion: Using IDF 2009 modified criteria, the prevalence of MS in the study series was 55.8%. The most common criteria for defining MS were: TG >= 95th percentile, BP >= 95th percentile, and blood glucose >= 100mg/ dl. Conclusions: Applying IDF 2009 criteria, 55.8% of the obese subjects presented 3-5 criteria, thus meeting the diagnostic criteria for MS in children.