Direct communication of the right pulmonary artery and the left atrium is an extremely rare congenital malformation of the pulmonary vasculature. A 41-year-old woman with a history of cyanosis since childhood presented with mild exertional dyspnea. On physical examination, she had central cyanosis, clubbing of the fingers, and an upright position caused by orthodeoxia. Imaging studies showed a very large aneurysm in the distal right pulmonary artery with a direct communication to the left atrium. The patient underwent successful repair, with resolution of hypoxia and exertional symptoms.