Umbilical cord blood transplantation is a rapidly growing form of treatment for m-any types of cancer and hematologic disorders. The concepts behind the use of umbilical cord blood transplantation are based on information gained from experience in bone marrow transplantation. Previously discarded as human waste, the blood in the umbilical cord remnant and the placenta has been observed to be rich in hematopoietic stem cells. Techniques for collecting these stem cells from the placenta may vary among the institutions, physicians, and other health care providers, including midwives and nurse practitioners, involved with this procedure. This source of hematopoietic stem cells in transplantation has many advantages, disadvantages, and controversies associated with its use.