We report a 3-year-old girl with hemophagocytic lymphohistiocytosis (HLH) who received BMT from an HLA-identical unrelated donor when the disease was active. She had entered remission in response to chemotherapy consisting of etoposide and methylprednisolone. After a relapse, her disease became refractory to chemotherapy, and splenectomy was performed with marginal improvement. She underwent BMT from an HLA-identical unrelated donor, conditioned with CY, TBI and anti-thymocyte globulin (ATG). She has been in complete remission for 18 months since the BMT. This result suggests that BMT from an HLA-identical unrelated donor should be considered for HLH even if the disease is active.