This article describes a public health orientation to drug and alcohol abuse prevention; reviews the state of the science underlying a risk and protective factor approach to alcohol and drug abuse prevention; describes Communities That Care, a community practice model that makes use of this evidence; and considers how this model reflects four important principles of social work practice. The intent of this article is to provide guidance to social workers who support the National Association of Social Work's intention to make prevention practice central to the provision of alcohol and drug abuse services by social workers.