- Behçet's disease is an inflammatory systemic disorder, characterized by a relapsing and remitting course, it manifests with oral and genital ulcerations, skin lesions, uveitis, vasculitis, central nervous system and gastrointestinal involvement. The main histopathological finding is widespread vasculitis of the arteries and veins. Therapy is variable and depends largely on the severity of the disease and organ involvement. There is common practice to treat with anticoagulation in patients suffering from vessel thrombosis, but there are no control trials to support this tendency. Anticoagulation treatment can cause major bleeding events in patients suffering from aneurysms. In this case report we describe a treatment dilemma in a patient suffering from deep vein thrombosis and pulmonary aneurysms.