The number of obese young people continues to rise, with a corresponding increase in extreme obesity and paediatric-adolescent bariatric surgery. We aimed to (i) systematically review the literature on bariatric surgery in children and adolescents; (ii) meta-analyse change in body mass index (BMI) 1-year post-surgery and (iii) report complications, co-morbidity resolution and health-related quality of life (HRQoL). A systematic literature search (1955-2013) was performed to examine adjustable gastric band, sleeve gastrectomy, Roux-en-Y gastric bypass or biliopancreatic diversions operations among obese children and adolescents. Change in BMI a year after surgery was meta-analysed using a random effects model. In total, 637 patients from 23 studies were included in the meta-analysis. There were significant decreases in BMI at 1 year (average weighted mean BMI difference: -13.5 kg m(-2) ; 95% confidence interval [CI] -14.1 to -11.9). Complications were inconsistently reported. There was some evidence of co-morbidity resolution and improvements in HRQol post-surgery. Bariatric surgery leads to significant short-term weight loss in obese children and adolescents. However, the risks of complications are not well defined in the literature. Long-term, prospectively designed studies, with clear reporting of complications and co-morbidity resolution, alongside measures of HRQol, are needed to firmly establish the harms and benefits of bariatric surgery in children and adolescents.