The National Institute of Justice NIJ has an emerging portfolio of research in the area of teen dating violence also known as adolescent relationship abuse. This article begins with a discussion of the developments that prompted NIJ to focus on teen dating violence. Next, the article highlights specific accomplishments and contributions that NIJ has made to helping develop knowledge and scientific understanding of adolescent relationship abuse, particularly around the prevention of teen dating violence perpetration and victimization. This is followed by a presentation of some of the key findings from NIJ-funded research. We then move to a discussion of some of the complex issues around definition, measurement and research methods and how NIJ has been involved in addressing those issues. The article concludes with some thoughts about the intersection of teen dating violence research, policy, and practice and highlights several research gaps that are in need of additional attention. Abstract published by arrangement with Sage.