There is a growing belief in the US that medicine is an altruistic profession, and that physicians display altruism in their daily work. We argue that one of the most fundamental features of medical professionalism is a fiduciary responsibility to patients, which implies a duty or obligation to act in patients' best medical interests. The term that best captures this sense of obligation is “beneficence”, which contrasts with “altruism” because the latter act is supererogatory and is beyond obligation. On the (...) other hand, we offer several examples in which patients act altruistically. If it is patients and not the doctors who are altruistic, then the patients are the gift-bearers and to that extent doctors owe them gratitude and respect for their many contributions to medicine. Recognising this might help us better understand the moral significance of the doctor-patient relationship in modern medicine. (shrink)