Behcet's disease is an inflammatory condition of multiple organ systems in witch recurrent oral and genital ulcers are the most typical signs. Less common clinical features include cerebral vasculitis, arterial aneurysm, deep vein phlebitis, aseptic meningitis, and discrete bowel ulcers. The most serious complication of Behcet's disease is arterial involvement especially ruptured arterial aneurysm. The aneurysm of sinus of Valsalva in Behcet's disease is a rare condition. There is no report about it in Korea. We report a case of a aneurysm of the sinus of valsalva with Behcet's disease. The patient had complete AV block and a right coronary sinus of Valsalva aneurysm which ruptured into the left ventricle. The diagnosis was made with transesophageal echocardiography. The patient was implanted with permanent pacemaker for relief of congestive heart failure due to complete atrioventricular (AV) block. He discharged and he is still follow-up in outpatient clinic.