In this chapter, theory regarding the development of intimate partner violence (IPV) and risk and protective factors for involvement in IPV are reviewed. In defining IPV, both perpetration of and victimization by acts of psychological, physical, and sexual aggression are considered, along with injuries, which are a key indicator of physical IPV. Organized within the levels of an ecological or dynamic developmental systems model, risk and protective factors are considered within the domains of (a) contextual characteristics of partners (demographic, neighborhood, community, and school factors), (b) developmental characteristics and behaviors of the partners (e.g., family, peer, psychological/behavioral, and cognitive factors), and (c) relationship influences and interactional patterns. Findings of a prior systematic review of risk factors (Capaldi et al. 2012) are summarized and extended by considering findings of recent reviews and empirical studies. Recommendations for prevention and intervention based on the review findings are presented.