Osler-Rendu-Weber Syndrome or hereditary hemorrhagic telangiectasia (HHT) is characterized by telangiecta-sia of the skin and of the mucous membranes and intermittent bleeding from vascular abnormalities; in about 20% of the patients pulmonary arteriovenous malformation is present. Pulmonary arteriovenous malformation is a congenital anomaly in the lung which causes shunting of venous blood in the pulmonary artery to systemic circulation, resulting in cyanosis, polycythemia and clubbing. Recently we experienced a case of multiple pul-monary arteriovenous malformation associated with the telangiectatic change of the cerebral artery in a 16-year-old male patient, which was confirmed by pulmonary angiography. (Korean Circulation J 2006;36:820-822) KEY WORDS：Osler-Rendu-Weber syndrome；Arteriovenous malformation；Telangiectasia, hereditary he-morrhagic.