Abstract: Medical complicity in torture is prohibited by international law and codes of professional ethics. But in the many countries in which torture is common, doctors frequently are expected to assist unethical acts that they are unable to prevent. Sometimes these doctors face a dilemma: they are asked to provide diagnoses or treatments that respond to genuine health needs but that also make further torture more likely or more effective. The duty to avoid complicity in torture then comes into conflict with the doctor’s duty to care for patients. Sometimes the right thing for a doctor to do requires complicity in torture. Whether this is the case depends on: the expected consequences of the doctor’s actions; the wishes of the patient; and the extent of the doctor’s complicity with wrongdoing. Medical associations can support physicians who face this dilemma while maintaining a commitment to clear principles denouncing torture.