This article reviews major issues of a developmental psychopathology understanding of youth violence and related insights gained from violence prevention efforts to date. Based in a perspective that emphasizes three areas of knowledge, epidemiology, risk factors and models, and developmental trajectories, findings are reviewed that help clarify theoretical propositions about the developmental patterns, influences, and pathways related to youth violence. Extant research is able to support several major contentions of basic developmental psychopathology theories of youth violence. Support is most robust for risk factors central to prevailing models of the development of youth violence. In addition to noting current knowledge contributions, the review suggests areas of needed additional analytic progress and theoretical extension to refine knowledge and expand understanding of the development of violence risk and its prevention.