Behcet's disease is a multisystem disorder with unknown etiology and a unique geographic distribution. The disease is characterized by recurrent skin-mucosa lesions and sight-threatening panuveitis. Vascular involvement, which is more common and more severe among males, has also equally characteristic features such as affecting mostly veins, having a significant tendency for thrombosis, and running a relapsing course. Lower extremity vein thrombosis (LEVT) is the most frequent manifestation, followed by vena cava inferior thrombosis. Pulmonary artery involvement (PAI), the most common form of arterial involvement, manifests as aneurysms and "in situ" thrombosis. PAI and Budd Chiari syndrome are the leading causes of increased mortality. In vascular cluster, typically, several types of venous or arterial vascular involvement may accumulate in the same individual. LEVI or cerebral venous sinus thrombosis is often present in these subgroups as the first event. Immunosuppressive treatment is essential in preventing the attacks and increasing survival. (C) 2016 Elsevier Ltd. All rights reserved.