Globalization has changed the logic of criminal policy in all different countries, as much because of what the phenomenon has meant regarding the internationalization of crime as because of the policy transfer. Policy transfer is the focus of this article and specifically in the case of the juvenile justice system in Spain. After a brief description of the policy transfer phenomenon and the supranational character of the juvenile justice system, the article attempts to explain the problems that can be found in a specific country, such as Spain when the policy transfer phenomenon occurs. The process of transferring two concrete methods taken on by this international doctrine, of clear Anglo-Saxon origin, to the Spanish juvenile justice system is analyzed. The two methods are the role of the juvenile instructor prosecutor and the methods which underlie the model of restorative justice. Throughout the analysis of the implementation of these practices in the Spanish juvenile justice system, the article shows the internal problems that these processes of policy transfer generate. What was revealed is the paradoxes implied in the process of policies transfer in the criminal sector. Although policy transfer has generalized, criminal policy in different countries is made more distinctive than ever by national, regional, and local resistance and differences. However, there is not a giving up on the convergence process of the different countries. There is a continuance and drive in studying it thoroughly. References