Severe arterial hypoxaemia or deteriorating pulmonary oxygenation due to HPS appears to be reversible within months of orthotopic liver transplantation. Due to the apparently poor prognosis in these patients, such abnormal oxygenation may, indeed, be considered an indication for liver transplantation in selected clinical situations. The pretransplant distinction between HPS and pulmonary hypertension as a reason for arterial hypoxaemia is essential, however, in that different outcomes appear to exist. Further prospective studies of patients with pulmonary vascular complications of liver disease are desperately needed.