A 38-year old male of severe aplastic anemia received allogeneic bone marrow transplantation. The patient was cared by isolation in the laminar air flow room, without elaborate decontamination techniques. The clinical course after transplantation was favorable except for the servere liver damage. The recovery of leukocytes was accelerated by using granulocyte-macrophage colony-stimulating factor. Infections complocation and actue graft versus host disease was not severe. The patient is alive 6 months after transplantation and chronic graft versus host disease is not observed.