A 14-year-old girl with acute lymphoblastic leukemia in second remission received an allogeneic marrow graft from her HLA identical brother. Cyclosporine A and short term methotrexate were given for prophylaxis against graft versus host disease. On day 42 post transplantation elevation of SGOT and SGPT was recognized, rising the next day to 8,560IU and 2,590IU, respectively. Prothrombin activity dropped below 10%. HCV antibody and HBs antigen were both negative. Fulminant hepatitis was diagnosed, therefore plasma exchange was initiated. However, hepatic encephalopathy developed and she died on day 57. The postmortem liver appearance was consistent with early changes of veno-occlusive disease. Such atypical cases of VOD with late onset are difficult to distinguish from fulminant hepatitis but should be kept in mind.