Prescription drug monitoring programs are statewide databases available to clinicians to track prescriptions of controlled medications. These programs may provide valuable information to assess the history and use of controlled substances and contribute to clinical decisionmaking in the emergency department (ED). The widespread availability of the programs raises important ethical issues about beneficence, nonmaleficence, respect for persons, justice, confidentiality, veracity, and physician autonomy. In this article, we review the ethical issues surrounding prescription drug monitoring programs and how those issues might be addressed to ensure the proper application of this tool in the ED. Clinical decisionmaking in regard to the appropriate use of opioids and other controlled substances is complex and should take into account all relevant clinical factors, including age, sex, clinical condition, medical history, medication history and potential drug-drug interactions, history of addiction or diversion, and disease state.