Pulmonary veno-occlusive disease (PVOD) is a rare cause of pulmonary hypertension. So far some 200 cases have been published worldwide. Since the latest classification, agreed at a meeting in Venice in 2003, PVOD is included in the group of pulmonary arterial hypertension (PAH). It has been hypothesized that it represents endothelial dysfunction of unknown cause. Although it has many features in common with idiopathic PAH, it partially differs from it phenotypically. After exclusion of known causes of pulmonary hypertension, such as diseases of pulmonary interstitial tissue, acral clubbing and rales suggest PVOD. The findings typical in the computed tomogram of the chest include prominent septal lines, centro-acinar opacities and mediastinal lymphadenopathy. In addition to arterial lesions PVOD is particularly characterized by lesions in the venous vascular bed. PVOD has a poor prognosis. Treatment with medication approved for PAH may carry the risk of pulmonary edema. Currently the immediate listing for lung- or combined lung-heart-transplantation is recommended, once the diagnosis of PVOD has been established.