The prognosis of patients with severely altered neurologic status remains difficult to predict, complicated as it has been by unclear diagnoses in many past studies. Consequently, recovery of consciousness in patients in a “persistent” vegetative state may be more frequent than was previously reported, leading to questions about the reliability of this diagnosis. Brain death may be defined in a number of ways and may not be an acceptable concept within some cultures. Nonetheless, the current pressures of organ transplantation lead us to refine our efforts at diagnosing this neurologic state and to continue to evaluate physiologic changes that may affect the quality of donated organs. The field of organ transplantation ethics is actively examining the issues of allocation of resources, obtaining organs from non-heart-beating donors, and xenografting.