We performed retrospective analysis of hepatic veno-occlusive disease (VOD) in 57 cases with leukemia after allogeneic bone marrow transplantation (BMT). Prostaglandin E1 (PGE1) was used to prevent VOD in 8 cases at a dose of 0.3 micrograms/kg/hr from day -8 to day 30. No VOD was noted in the PGE1 group, while the incidence of VOD was 8/49 (16.3%) in the non PGE1 group. In twelve patients with pretransplant liver dysfunction, VOD was noted in 0/3 in the PGE1 group and 4/9 (44.4%) in the non PGE1 group, respectively. However, prophylactic effects of PGE1 on VOD is not significant in this study, so further studies are needed to determine the efficacy of PGE1. One of 8 patients with PGE1 prophylaxis had edema and erythema on extremities, however, severe toxicity was not experienced.