Behçet's disease (BD) is a systemic disorder and vasculitis is a common pathologic finding that may give clues in the understanding of the vascular involvement. During the period between 1968 and 1988, 30 patients with BD had vascular complications that were diagnosed by conventional venography (indud ing cavography) (in 15 patients prior to 1985) and then by computed tomography, digital subtraction angiography (DSA), and sonography in the remaining 15 patients for the last four years . The group included 13 patients with superior vena caval obstruction (SVCO), 3 with inferior vena caval obstruction (IVCO), 4 with both SVCO and IVCO, 2 with IVCO and hepatic veins obstruction (Budd-Chiari syndrome, BCS), 1 patient with SVCO, IVCO, and BCS, 1 with BCS, 1 with portal vein and IVCO, 4 patients pulmonary artery occlusion (1 of them also had pulmonary artery aneurysm), and finally, 1 patient with right illiac artery aneurysm. In many cases, classical clinical features of BD were not evident when great vessels were involved. The authors concluded that DSA and sonography are the preferred method in demonstrating vascular complications of BD and that BD should be taken into consideration when a patient presents with a great vessel involvement due to unknown cause.