Hepatopulmonary syndrome is an important complication of chronic liver disease occurring in 16 24% of patients. It is characterized by an increase in alveolar -capillary gradient, with or without hypoxemia, due to intrapulmonary vasodilatation. The course of the disease is progressive and associated with increased morbidity and mortality. There is no effective medical treatment and liver transplant is a priority. To exemplify the authors present the case of a 39 year -old male patient sent to the Pulmonology outpatient clinic and presenting with secondary polycythemia and progressive exertional dyspnoea. Clinical investigation identified a hepatopulmonary syndrome.