Pulmonary veno-occlusive disease (PVOD) is a rare but life-threatening disease. Although prostacyclin (PGI2) attenuates pulmonary hypertension and improves the prognosis in patients with primary pulmonary hypertension, little information is available regarding the effect of PGI2 on patients with PVOD. This report describes a patient with severe PVOD who showed marked improvement in exercise capacity and pulmonary hemodynamics with continuous IV PGI2 treatment. Furthermore, he experienced no clinical events for 12 months and survived for 25 months after the initiation of PGI2 therapy. These results suggest that continuous IV PGI2 therapy may serve as a bridge to transplantation in some cases of PVOD.