Report by the Pres. Council on Bioethics of an inquiry that was occasioned by another forthcoming Council report on ethical questions in organ transplantation. The two reports are linked ethically: most of the organs procured for transplantation in this country come from deceased donors who have been declared dead in accord with the neurological standard (NS). This report is primarily concerned with a careful analysis of the ethical questions raised by the NS, i.e., the clinical determination of ¿whole brain death.¿ Since then, the NS has been accepted as one of two valid standards for determining death and has been adopted in many countries throughout the world. The Council has concluded that the NS remains valid.