There is a growing interest in advance directives in health care. In a number of jurisdictions the legal status of advance directives is regulated by law, or legal regulation is being discussed. Advance directives have emerged as a vehicle for people to control post-competence medical interventions.1 In an advance directive, a person can formulate his or her personal preferences and wishes with regard to medical treatment and care in case of future incompetence, and so he or she can try to maintain a measure of autonomy even after having become incompetent. An advance directive may also designate an agent who will ultimately be responsible for implementing the declarant’s instructions, or, in the absence of discernible instructions, for making medical decisions on behalf of the incompetent patient. The dominant view is that by executing an advance directive a person can exhibit so-called prospective autonomy.2 A refusal of treatment that is formulated in an advance directive is generally considered to operate as an extension of a competent patient’s moral and legal right to refuse treatment, based on the principle of respect for autonomy and individual self-determination.3 The dominant ethical and legal point of view is that a refusal of treatment by a competent patient should be respected, even if we think that this decision is unwise, and even if this refusal may lead to an earlier death of the patient.4 Exemplary for the role of advance directives in the context of patient self-determination is the following statement of the American Academy of Neurology Ethics and Humanities Subcommittee (1996): “Completing and following advance directives (in dementia) is desirable ethically because it permits a type of patient self-determination even in states of incompetence.” (p.1181) The potential benefits of advance directives are obvious. Not only can persons prospectively promote personal values and conceptualizations of dignity, but also the ultimate decision-makers on behalf of the incompetent patient can receive crucial guidance.5