Since the beginning of hematopoietic stem cell harvesting from volunteer unrelated donors, ensuring donor safety has been a necessary goal of all parties involved in the process. As donation of BM or PBSCs is not in the interest of the donor's own physical health, donor registries and transplantation centers must take into account both medical and ethical aspects involved in the donation procedure. One of the principal goals leading to the formation of the World Marrow Donor Association (WMDA) was to establish internationally acceptable standards for all aspects of unrelated donor care.