Bone Marrow Donors Worldwide (BMDW) represent continuing efforts to collect HLA phenotypes of volunteer stem cell donors and cord blood units, being responsible for co-ordination of their worldwide distribution. Participants are 59 stem cell donor registries from 43 countries, and 40 cord blood banks from 25 countries. BMDW started as an initiative of the Immunobiology Working Party of the European Group of Blood and Marrow Transplantation (EBMT) in 1988. In February 1989, the first edition was distributed, which contained donor files of eight registries with a total of 155,000 volunteer stem cell donors. The current number of donors and cord blood units in the BMDW database is 12,092,374.