BACKGROUND: Vascular complications can be seen in patients with Behçet's disease. Arterial and venous complications may be found separately or concomitantly in patients. PATIENTS AND METHODS: Out of 29 patients with vasculo-Behçet's disease 7 patients with multiple aneurysms and venous lesions were documented over a period of 20 years. All patients were male, ranging in age from 24 to 52 years. The mean duration of the disease was 6 +/- 2 years. The aneurysms were found in the following locations: one pulmonary artery, two abdominal aorta, four iliac, five femoral, and two popliteal artery. Both aneurysmal and occlusive lesions were present in three patients. In the venous lesions associated with the aneurysms there were three deep and three superficial venous thrombosis. Two patients had caval involvement-superior and inferior vena caval syndromes. RESULTS: We performed seven interposition grafting by polytetrafloroethylene, one Y-grafting, one aneurysmorrhaphy, one lobectomy. Re-anastomosis was performed in two patients who had anastomotic aneurysms and graft occlusion without disabling ischemia. Venous pathologies were treated by medical therapy. The patients were followed up between 1 to 8 years. One of the patients with iliac artery aneurysm died due to gastrointestinal bleeding 15 months after the operation. CONCLUSIONS: In conclusion, when an aneurysm has been found in a patient with Behçet's disease, the patient should be scanned for possible multiple aneurysms and venous lesions since they might be found together. Surgical treatment, when feasible, should be performed in cases with Behçet aneurysms because of a high risk of rupture. However, the possibility of an anastomotic aneurysm developing after surgery should also be kept in mind.