The independent, nonfederal Task Force on Community Preventive Services (Task Force), which directs the development of the Guide to Community Preventive Services (Community Guide), conducted a systematic review of published scientific evidence concerning the effectiveness of laws and policies that facilitate the transfer of juveniles to the adult criminal justice system to determine whether these transfers prevent or reduce violence among youth who have been transferred and among the juvenile population as a whole. For this review, transfer is defined as placing juveniles aged <18 years under the jurisdiction of the adult criminal justice system. The review followed Community Guide methods for conducting a systematic review of literature and for providing recommendations to public health decision makers. Available evidence indicates that transfer to the adult criminal justice system typically increases rather than decreases rates of violence among transferred youth. Available evidence was insufficient to determine the effect of transfer laws and policies on levels of violent crime in the overall juvenile population. On the basis of these findings, the Task Force recommends against laws or policies facilitating the transfer of juveniles to the adult criminal justice system for the purpose of reducing violence.