Pulmonary arteriovenous fistula is a congenital vascular malformation in lung resulting from abnormal capillary development and the exact etiology is not well known but it may occur with or without hereditary hemorrhagic telangiectasia. Hereditary hemorrhagic telangiectasia (L-IHT) or Rendu-Osler-Weber disease is an autosomal dominant vascular disorder which associates epistaxis, mucocutaneous and visceral telangicetases, and recurrent hemorrhage with chronic anemia and visceral shuntings. Recently we experienced a case of the pulmonary arteriovenous fistula in a 23 year old woman with a family history of this disease, which was confirmed by pulmonary angiography.