Transplantation of blood cells harvested from the umbilical cord immediately after birth has been effective in repopulating the bone marrow. These placental blood transplantations may be safer than conventional bone marrow transplantations and may suspend the need to harvest bone marrow, a process fraught with difficulties. Further understanding and advancement of this emerging technology require developing large banks of placental blood. In this article, we examine some of the ethical issues associated with placental blood banking, including (1) questions about ownership of the tissue, (2) the necessity and nature of obtaining informed consent from parents for harvesting placental blood and the information-gathering process associated with it, (3) obligations to notify parents and children of the results of medical testing for infectious diseases and genetic information, (4) matters of privacy and confidentiality related to such information, and (5) the need for fair and equitable harvesting of and access to placental blood.