Natural Death Acts have been enacted in eight states in an effort to permit terminally ill patients an opportunity to refuse extraordinary therapeutic measures. In part, these laws reflect fear of a painful, lingering terminal illness which actually occurs in a very small minority of patients. These acts fail to take into account that (1) a small but significant fraction of patients judged terminal by their attending physicians survive for a much longer time than predicted and even recover, (2) in many cases, “extraordinary therapy” will restore critically ill or even unconscious patients to functional life, (3) with the rapid advances in medical science, “extraordinary measures” may quickly become commonplace therapy, and (4) “extraordinary therapy” often makes a terminal illness less painful and distressing. The difficulties surrounding revocation of a directive under a Natural Death Act by an unconscious or seriously incapacitated patient require additional safeguards. Adequate due process should be assured before Natural Death Act provisions are applied to incompetent persons or minors. Substitution of brain death for the common law definition would permit withdrawal of useless life-support measures. Natural Death Acts may be largely superfluous in view of the balance between established common law principles of the state's interest in preservation of life and the individual's right to privacy and to refuse therapy. The interests of incompetent or minor persons can be safeguarded by application of the doctrine of “substituted judgement” by the courts. A discussion of major legal decisions relating to the right to withhold treatment and under what circumstances is reviewed in the context of the Natural Death Acts, and recent definitions of brain death.