Statistical metaanalyses is seen as helpful in synthesizing results of primary studies on the treatment of juvenile offenders. This study evaluated the designs and the findings from statistical metaanalyses on the effects of residential treatment for juvenile offenders by means of a second-order narrative review. The study attempts to find out what were the mean effects of residential treatment for young offenders reported in statistical metaanalyses, to critically discuss the advantages and drawbacks of metaanalysis as a method of research synthesis in this field, and to point to certain key elements on which future syntheses of research on the effects of residential treatment for juvenile offenders should focus. The metaanalyses were selected by means of a stepwise approach. The list of selected metaanalytic studies was reduced by excluding metaanalyses dealing only either with adult offenders or with community-based interventions. The evaluation of metaanalyses was conducted by means of a narrative review. The review provided answers to two basic questions: (1) were the effects of treatment large and (2) which variables influenced treatment effects? Treatment of juvenile offenders produced an average reduction of recidivism by about 9 percent. The review showed that the “nothing works” hypothesis, concerning treatment effects for juvenile offenders, could be replaced by moderate optimism. Recommendations for future research suggest a focus on European contexts and multiple measures to evaluate long-term effects. References