Chronic liver disease is well known to be associated with pulmonary abnormalities. Hypoxemia, clubbing, cyanosis and hyperventilation are common. The hypoxemia in cirrhotic patients has several causes: diffuse shunts due to intrapulmonary arteriolar vasodilatation, impaired hypoxic vasoconstriction, impaired matching of ventilation to perfusion, pleural effusions and diaphragmatic dysfunction. Because of gravity, shifting of blood to the dilated precapillary beds of the lung bases results in an increased hypoxemic dyspnea when the patient is in the upright position, also known as orthodeoxia and platypnea. It has only been described in 5% of the cirrhotic patients and has not been described in a Belgian refereed journal (Medline literature search 1983-Aug 1993). It should be considered in the initial differential diagnosis of hypoxemia in patients with liver cirrhosis and dyspnea. Measuring arterial blood gases in the lying and upright position can prevent further invasive investigations, and whole body nuclide scan with technetium-99m macroaggregated albumin can confirm the diagnosis. Standard therapy with spironolactone (Aldactone) can worsen the condition and we found no additional benefit of beta-antagonists (propranolol/Inderal) in the reduction of the shunt fraction, probably because the main reason for the shunting is precapillary vasodilatation. Since there are no anatomical porto-pulmonary shunts, surgery is also inappropriate. The only therapy consists of oxygen supplements and low dose diuretics in patients with edema.