The International Bone Marrow Transplant Registry (IBMTR) and the Autologous Blood and Marrow Transplant Registry (ABMTR) are international research organizations that collect and analyze data on recipients of allogeneic and autologous hematopoietic stem cell transplants, respectively. Over 300 institutions in 47 countries contribute data to the IBMTR and over 150 institutions in North and South America contribute data to the ABMTR. The IBMTR and ABMTR database have information on more than 65,000 transplant recipients, about 40% of allogeneic transplantations performed since 1964, and about half of all autotransplantations in North and South America since 1989. Current transplant activity, as reported to the IBMTR and ABMTR, is summarized in this article as well as key findings from recent IBMTR and ABMTR studies.