Providing care to individuals with substance use disorders raises legal and ethical issues. The two major legal issues are regulation of scheduled drugs and patient confidentiality. Many patients make poor choices; nevertheless, all deserve medical care incorporating the principles of ethical care. General ethical principles apply to the treatment of substance use disorders. These include autonomy, beneficence, nonmaleficence, justice, fidelity, and futility. Treatment of individuals with substance use disorders may create situations in which there is conflict or disagreement with clinicians. Effective strategies can help avoid or mitigate dilemmas. Drug testing, employment, and pregnancy raise specific legal and ethical issues.