The practice of emergency medicine routinely requires rapid decisionmaking regarding various interventions and therapies. Such decisions should be based on the expected risks and benefits to the patient, family, and society. At times, certain interventions and therapies may be considered "futile," or of low expected likelihood of benefit to the patient. Various interpretations of the term "futility" and its practical application to the practice of emergency medicine are explored, as well as background information and potential application of various legal, ethical, and organizational policies regarding the determination of "futility. "Decisions regarding potential benefit of interventions should be based on scientific evidence, societal consensus, and professional standards, not on individual bias regarding quality of life or other subjective matters. Physicians are under no ethical obligation to provide treatments they judge to have no realistic likelihood of benefit to the patient. Decisions to withhold treatment should be made with careful consideration of scientific evidence of likelihood of medical benefit, other benefits (including intangible benefits), potential risks of the proposed intervention, patient preferences, and family wishes. When certain interventions are withheld, special efforts should be made to maintain effective communication, comfort, support, and counseling for the patient, family, and friends.