Background Metabolic syndrome (MeS) is a group of physiological, biochemical, clinical, and metabolic factors which increase the incidence of atherosclerosis, type 2 diabetes mellitus, and early mortality. Overall prevalence of MeS is around 3.3%, 11.9% in overweight, 29.2% in obese, and less than 1% in non-obese children. Nearly, 90% of obese children and adolescents have at least one parameter of MeS. Objective Clinical and metabolic evaluation of obese adolescents before and after laparoscopic sleeve gastrectomy (LSG). Subjects and methods Prospective study included analysis of data from 35 adolescents (12-19 years) with body mass index (BMI) above 99th percentile for age and sex. All of them had metabolic syndrome and were submitted to LSG between 2015 and 2017. Anthropometric measurements, clinical and laboratory assessment were performed, preoperatively, 6, 12, and 24 months postoperatively. Results Mean age was 16.43 years and mean preoperative weight and BMI were 132.68 kg and 48.90, respectively. Mean excess weight loss (EWL) was 54.11 kg after 12 months' and 51.19 kg after 24-months post-LSG, corresponding to 74 and 73 EWL%, respectively, as well as mean BMI loss (BML) of 19.89 and 18.7 kg/m 2. LSG improved fatty infiltration of liver in 93% of cases and other comorbidities in 100% of patients. Conclusions Laparoscopic sleeve gastrectomy (LSG) proved as a safe and effective procedure for adolescent obesity and its related metabolic morbidities.