Pulmonary veno-occlusive disease is a rare cause of pulmonary hypertension in patients with systemic sclerosis that can be misclassified as pulmonary arterial hypertension. Differentiation between pulmonary veno-occlusive disease and pulmonary arterial hypertension is challenging because of the similar clinical picture. Nevertheless, discrimination is important because pulmonary veno-occlusive disease has a worse prognosis. Vasodilators including phosphodiesterase type 5 inhibitors and endothelin receptor antagonists should be started with caution and often in combination with diuretics to prevent pulmonary edema.