Consensually established principles of clinical conduct, known variously as practice guidelines, standards, protocols, or algorithms, have proliferated throughout medicine over the past decade. Institutional and disciplinary efforts to develop and promulgate guidelines for the treatment of additive disorders have recently been initiated. We review guideline development activities of the American Psychiatric Association, American Psychological Association, American Society of Addiction Medicine, American Nurses Association, National Association of Social Workers, and Center for Substance Abuse Treatment of the Substance Abuse and Mental Health Services Administration. Medical care performance and outcome assessments are discussed with attention to the role they can play in evaluating and refining guidelines. Potential effects of guidelines, salutary and deleterious, on clinical practice in the addictions are delineated.