The results show that for an AD to apply in an emergency situation certain standards are necessary that assure the practicability, especially if a patient does not wish to be resuscitated. Most difficulties with ADs occurred with imprecise formulation, text length and inconsistency of statements. The following instructions were usually missing: hierarchy of those given power of attorney and specification on medication, information about the scope of the ADs, statement about resuscitation, extent and limitations of the desired treatment, especially with patients certified as terminally ill and instructions on who should decide about medical treatment in a conflict situation. A so-called emergency instruction which gives on a single page the patient's statement on resuscitation would have been very helpful in individual cases. The results suggest that patients may need more information and education about AD to guarantee patients rights and self-determination.