Background: Child and adolescent overweight and obesity have increased globally, and are associated with significant short and long term health consequences. Objectives: To assess the effects of surgical interventions for treating obesity in childhood and adolescence. Search methods: We searched the Cochrane Library,MEDLINE, PubMed, EMBASE as well as LILACS, ICTRP Search Portal and ClinicalTrials.gov (all from database inception to March 2015). References of identified studies and systematic reviews were checked.No language restrictions were applied. Selection criteria: We selected randomised controlled trials (RCTs) of surgical interventions for treating obesity in children and adolescents (age < 18 years) with a minimum of six months follow-up. Interventions that specifically dealt with the treatment of eating disorders or type 2 diabetes, or included participants with a secondary or syndromic cause of obesity were excluded. Pregnant females were also excluded. Data collection and analysis: Two review authors independently assessed risk of bias and extracted data. Where necessary authors were contacted for additional information. Main results: We included one RCT (a total of 50 participants, 25 in both the intervention and comparator group). The intervention focused on laparoscopic adjustable gastric banding surgery, which was compared to a control group receiving a multi component lifestyle programme. The participating population consisted of Australian adolescents (a higher proportion of girls than boys) aged 14 to 18 years, with a mean age of 16.5 and 16.6 years in the gastric banding and lifestyle group, respectively which was conducted in a private hospital, receiving funding from the gastric banding manufacturer. The study authors were unable to blind participants, personnel and outcome assessors which may have resulted in a high risk of performance and detection bias. Attrition bias was noted as well. The study authors reported a mean reduction in weight of 34.6 kg (95% confidence interval (CI) 30.2 to 39.0) at two years, representing a change in body mass index (BMI) of 12.7 (95% CI 11.3 to 14.2) for the surgery intervention; and a mean reduction in weight of 3.0kg (95% CI 2.1 to 8.1) representing a change in BMI of 1.3 (95% CI 0.4 to 2.9) for the lifestyle intervention. The differences between groups were statistically significant for all weight measures at 24 months (P < 0.001). The overall quality of the evidence according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) was low. Adverse events were reported in 12/25 (48%) participants in the intervention group compared to 11/25 (44%) in the control group (low quality evidence). A total of 28% of the adolescents undergoing gastric banding required revisional surgery. No data were reported for all-cause mortality, behaviour change, participants views of the intervention and socioeconomic effects. At two years, the gastric banding group performed better than the lifestyle group in two of eight health-related quality of life concepts (very low quality evidence) as measured by the Child Health Questionnaire (physical functioning score (94 versus 78, community norm 95) and change in health score (4.4 versus 3.6, community norm 3.5)). Authors’ conclusions: Laparoscopic gastric banding led to greater body weight loss compared to a multi component lifestyle program in one small study with 50 patients. These results do not provide enough data to assess efficacy across populations from different countries, socioeconomic and ethnic backgrounds, whomay respond differently. This systematic review highlights the lack of RCTs in this field. Future studies should assess the impact of the surgical procedure and post operative care to minimise adverse events, including the need for post operative adjustments and revisional surgery. Long-term follow-up is also critical to comprehensively assess the impact of surgery as participants enter adulthood.