Purpose To determine what factors contribute to the effi- cacy of non-drug treatments designed to promote weight loss in overweight and obese adolescents. Methods Data sources Medline/PubMed; Psychinfo; EMBASE; Web of Science (ISI); and Cochrane Central Register of Controlled Trials. Study selection Randomized clinical trials of treatments for obesity and overweight in adolescents aged 10–19 years with a minimum duration of 2 months. Data extraction 115 of the 12,948 publications retrieved met eligibility criteria and 26 were included in the final sample. Period of extraction January 2004 to November 2014. Results The Delphi list was used to evaluate the methodological quality of the studies (M = 5.58, SD = 1.027). There was considerable variability between the interventions, but they were all multifactorial, with components such as nutritional education, physical activity, family support and psychological therapy. The number of contacts with subjects during the course of the intervention was a predictor of treatment efficacy when the groups were compared. Limitations This systematic review was limited to trials reported in English and by the lack of methodological rigor and shortcomings in reporting in the studies reviewed. Conclusions Multidisciplinary interventions including family support and guided behavior modification appear to be effective methods of reducing BMI in overweight and obese adolescents.