For the purposes of this chapter, "intimate partner violence" refers to "any behavior within an intimate relationship that causes physical, psychological, or sexual harm to those in the relationship." In 48 population-based surveys from around the world, between 10 percent and 69 percent of women reported being physically assaulted by an intimate male partner at some point in their lives. Most women who are targets of physical aggression generally experience multiple acts of aggression over time. A discussion of the dynamics of partner violence notes that recent research from industrialized countries suggests that the forms of partner violence that occur are not the same for all couples who experience violent conflict. There are apparently at least two patterns. These are a severe and escalating form of violence characterized by multiple forms of abuse and a more moderate form of relationship violence in which continuing frustration and anger occasionally erupt into physical aggression. In discussing how women respond to abuse, the chapter advises that according to research, leaving an abusive relationship is a process. Most women leave and return several times before finally deciding to end the relationship. A discussion of the risk factors for intimate partner violence focuses on individual factors (history of violence in the perpetrator's family of origin, alcohol use by men, and personality disorders); relationship factors (marital conflict); community factors (rates of other violent crime, social capital, social norms elated to family privacy, and community norms related to male authority over women); and societal factors (cultural factors and wider social conflict). A section of the chapter on the consequences of intimate partner violence considers the impact on the victim's health, including reproductive health, physical health, and mental health; the economic impact of intimate partner violence (lost productivity and increased use of social services); and the impact on children (emotional and behavioral problems that stem from witnessing violence in the home). A section on the prevention of intimate partner violence considers support for victims (shelters and women's crisis centers); legal remedies and judicial reforms (criminalizing abuse, laws and policies on arrest, alternative sanctions, and all-women police stations); treatment for abusers; health service interventions; and community-based efforts (outreach work, coordinated community interventions, prevention campaigns, and school programs). Principles of good practice are suggested for action at all levels of governmental and collective action, women's involvement, changing institutional cultures, and multisectoral approaches. Recommendations pertain to research on intimate partner violence, the strengthening of informal sources of support, making common cause with other social programs, and investing in primary prevention. "Boxes" within the chapter provide brief discussions of making data on intimate partner violence more comparable, a study of responses to domestic violence, and some examples of primary prevention programs throughout the world. 6 tables and 216 references