Definition of the problem In the health care systems of multicultural societies, we encounter a number of ethical conflicts, in which cultural and religious values play a decisive role. These problems can turn out to be very complex, when the patient is no longer able to decide on medical treatment by him- or herself. It is legitimate to ask whether an advance directive (living will) can contribute to solving such problems. In this article I discuss the ethical aspects of the medical treatment of Muslim patients and the implementation of advance directives by this clientele. Arguments and conclusion The pluralistic attitudes towards end-of-life decisions within the Islamic world itself, the influence of family and traditional values, heterogeneous forms of religiousness in the Muslim population and different health care systems in each particular country provide the most important normative implications for the implementation of culturally sensitive advance directives by Muslim patients. Despite many persisting difficulties, a culturally sensitive advance directive can improve consideration for and realization of the presumed will of Muslim patients at a point at which they have become unable to express themselves any longer.