We report a case of Behcet's disease complicated by aortic aneurysm and contiguous vena cava thrombosis due to compression. Arterial aneurysms are uncommon in the course of Behcet's disease and are associated with a poor prognosis owing to the risk of rupture. Vena cava thrombosis is found in 10% of cases; pulmonary embolism is infrequent. Venous and arterial lesions usually evolve independently. In most cases they are consecutive to vasculitis. The case reported herein is uncommon because of simultaneous and contiguous venous and arterial lesions. Eighteen months after aorto bi-iliac graft and inferior vena cava ligature, there is no recurrence of thrombosis nor aneurysm with a treatment including heparin, colchicine and azathioprine.