This brief essay outlines the progression over the last 20 years of ecological theories of interpersonal violence. The period between the present and the early 1980s began with a revival of cultural explanations of violence that paralleled the introduction of the neo-conservative social science and then witnessed a rediscovery of deficits-based structural explanations of interpersonal violence under the broad rubric of social disorganization theory. The essay concludes with a more optimistic appraisal of recent refinements of social disorganization theory that consider the mediating effects of collective efficacy on urban crime and interpersonal violence.