This research applies the social disorganization perspective on the neighborhood-level determinants of crime to partner violence. The analysis brings data from the 1990 Decennial Census together with data from the 1994–1995 Project on Human Development in Chicago Neighborhoods Community Survey, the 1994–1995 Chicago homicide data, and data from the 1995–1997 Chicago Health and Social Life Survey. The findings of this study indicate that collective efficacy—neighborhood cohesion and informal social control capacity—is negatively associated with both intimate homicide rates and nonlethal partner violence. Collective efficacy exerts a more powerful regulatory effect on nonlethal violence in neighborhoods where tolerance of intimate violence is low. Collective efficacy also increases the likelihood that women will disclose conflict in their relationships to various potential sources of support.