The premise of this special issue is that an understanding of juvenile delinquency and juvenile justice in other countries would provide each country with new information, fresh theoretical perspectives, and ideas for understanding and addressing the problem of juvenile delinquency. The comparative approach exposes the reader to information, regarding innovations and historically successful programs for each respective country to consider. It is hoped that one nation's success and/or failure may stimulate the thinking of other nations. However, it is important to note that valid theories or successful programs may be limited to the population that was used as the basis of the theory or program. This article focuses on the benefits of the comparative approach, and the need for a systematic approach to collecting data on juvenile delinquency and juvenile justice. © 1992, Taylor & Francis Group, LLC. All rights reserved. © 2016 Elsevier B.V., All rights reserved.