Pulmonary arteriovenous fistula is a rare congenital vascular malformation in the lung, resulting from erroneous capillary development, with incomplete formation or disintegration of the vascular septa that would normally divide the primitive connection between the venous and arterial plexus. The pathogenesis of its symptom is that unoxygenated and desaturated arterial blood enter into the pulmonary venous system directly. Recently we have experienced a case of multiple pulmonary arteriovenous fistula in a 15 year old male patient, who presented the symptom of cyanosis and dyspnea on exertion. The operation revealed well circumscribed and multilobulated aneurysmal lesion in left lower lobe with its subpleural and posterolateral basal location, and another aneurysmal lesion in inferior lingular segment of left lung. There was no abnormal connection between the fistula and systemic circulation. The left lower lobectomy was performed along with local extirpation of the inferior lingular segment of left lung. Both lesions showed angiomatous dilatation of the various sized vessels embedded in the parenchyma microscopically. Postoperative clinical course disclosed much improvement in symptoms and in the value of blood gas analysis. The patient was discharged without any complication.