Venous thrombosis, including superior and inferiorvena caval occlusion is considered an integral manifestation of Behçet’s disease. In this series, 5 of 11 patients (45.4%) with active Behçet’s disease had clinical evidence of present or past venous thrombosis. The mean euglobulin lysis time in the 11 subjects was found to be within the normal range: however, in 3 patients, significant impairment of fibrinolytic activity was demonstrated. Inhibition of systemic fibrinolysis may be a contributory factor in the pathogenesis of the thrombotic diathesis characteristic of Behçet’s disease.