RESUMO
Umbilical cord blood is an attractive source of hematopoietic stem cells in allogeneic hematopoietic stem cell transplantation. Umbilical cord blood transplantation has merits of rapid availability and low risk of severe acute graft versus host disease. Umbilical cord blood should be an important source of stem cell transplantation for patients who have no suitable human leukocyte antigen-matched bone marrow, or peripheral stem cell donor. Transplantation of umbilical cord blood is limited by insufficient cell doses. This had led to the alternative concept of attempting to increase the number of cell doses using two cord blood units from different donor. We report a case of double-unit cord blood transplantation for 55-year-old male with primary refractory acute myeloid leukemia.