Portopulmonary hypertension (PoPH) is a rare but life-threatening complication of portal hypertension that is characterised by proliferative changes in the pulmonary microvasculature indistinguishable from other forms of pulmonary arterial hypertension (PAH). Although PoPH is most commonly observed in the setting of cirrhosis, patients with non-cirrhotic portal hypertension are also at risk of developing the disorder. A definitive diagnosis requires invasive haemodynamic confirmation by right heart catheterisation and screening for PoPH should be routinely performed in all patients being considered for liver transplantation. Although severe PoPH is considered a contraindication to liver transplantation, there is now compelling data supporting the use of PAH-specific therapies with the aim of improving pulmonary haemodynamics to allow transplantation to be successfully performed. This review explores possible relevant aetiological factors and summarises current diagnostic and therapeutic approaches for PoPH patients.