As a result of recent media coverage of cord blood transplantation, expectant parents increasingly ask perinatal caregivers about the possibility of collecting and saving their newborn child's umbilical cord blood. Umbilical cord blood has been used as a source of hematopoeitic stem cells for the treatment of human disease since 1988. As a result of these initial successes, cord blood collection, banking, and transplantation has become increasingly used worldwide, giving rise to several controversies. We have reviewed the current status of the indications for cord blood collection, the methods of collection, and safety issues related to the cyropreservation of cord blood units. In addition, the clinical success of cord blood transplants from related and unrelated donors is detailed. We have examined the major issues concerning cord blood transplantation as it exists in the year 2000 to provide insight into this exciting area of clinical investigation.