Adolescence is a unique developmental period in which youth are at heightened risk for violence perpetration and victimization, both of which can adversely affect the course of normal psychosocial development and health across the life course. The possible range of violent experiences during adolescence is broad, including physical and relational peer violence, bullying, sexual violence, cyber-aggression, child maltreatment, exposure to parental intimate partner violence, exposure to aggressive media, and more. The 8 articles in this special issue span this wide range of violence experiences. In helping to fill gaps in knowledge about the nature and processes by which violence develops, and how violence experiences affect adolescents, these articles as a group also offer direction for future research. They illustrate the need for research that cuts across the separate bodies of research on violence involving youth, that tackles thorny questions about the conceptualization of violence in its myriad forms, and that considers the ways in which the various forms and dimensions of violence operate together, across levels of the social ecology, to influence outcomes. The findings in this collection of studies also have implications for the development of prevention and intervention programs to address the problem of violence in adolescence. (PsycINFO Database Record (c) 2013 APA, all rights reserved)