Behçet's disease is a chronic systemic inflammatory disorder with an unknown etiology. It affects many organs and is characterized by recurrent attacks. Pulmonary artery aneurysms occur more frequent in males, and it is o ne of the rare pulmonary complications of Behçet's disease. It has a poor and prognosis, and is also one of the leading causes of death from Behçet's disease. Here we report a case of suspected Behçet's disease diagnosed by a manifestation of a pulmonary artery aneurysm in a 37-year-old woman.