Caring for patients from different cultural or religious backgrounds may create difficult ethical dilemmas for physicians. The article reviews four case histories, involving patients from the Navajo culture or the Christian Science Church, that highlight some of these ethical problems. It then discusses an "ethics of responsibility," which is based on and encompasses a variety of meanings of responsibility, including responsibility as recognition, as taking charge, as the ability to assess the consequences of one's actions, and as making a commitment. An ethics of responsibility provides a novel perspective for resolving ethical problems in medicine.