ObjectiveThis article was written to argue that physicians are not ethically obligated to provide care which they consider futile, unreasonable, or both, either voluntarily or in response to patient or surrogate demands.Data SourcesData used to prepare this article were drawn from published articles, including original investigations, position papers, and editorials in the author's personal files.Study SelectionArticles were selected for their relevance to the subjects of medical ethics, the concepts of futility and medical reasonableness, case law, and healthcare reform.Data ExtractionThe author extracted all applicable data.Data SynthesisPhysicians may feel obligated to provide care in all clinical circumstances due to the single master view of medicine and the ethical principle of autonomy. However, care may be considered futile according to several definitions of that word, including that which describes futile treatment as something that does not benefit the patient as a whole. Furthermore, care may be considered unreasonable if it is excessive and not generally agreed upon. Physician refusal to provide futile or unreasonable care is supported by the ethical principles of nonmaleficence, beneficence, and distributive justice. The last principle is particularly relevant in the current climate of healthcare reform.ConclusionsAlthough the issue of physician refusal of requested care has not been resolved by case law or legal statute, it is supported by compelling ethical principles. Physicians are not ethically required to provide futile or unreasonable care, especially to patients who are brain dead, vegetative, critically or terminally ill with little chance of recovery, and unlikely to benefit from cardiopulmonary resuscitation.(Crit Care Med 1995; 23:760-766)