Advance directives were developed to preserve the freedom and autonomy of patients who no longer can express or assert their wishes and to protect them from intrusive, often futile therapy. Patients' choices depend upon their value systems and, in a general way, advance directives seek to take these values into account This paper reviews attempts to ascertain patients' values through the Standard Gamble Test, questionnaires, illness scenarios and narrative inquiries. The narrative enquiry seems best adapted to obtaining valid directives because it takes into account patients' life histories and experience.