Behçet's disease is a systemic disorder with the histopathological correlate of leukocytoclastic vasculitis. Pathogenetically, besides a strong genetic component participation of the innate immune system and an autoinflammatory component are discussed. The disease is most common in countries along the former silk route but in Germany the disease is rare (prevalence approximately 0.6/100,000). Oral aphthous ulcers are the main symptom, followed by skin manifestations, genital ulcers and oligoarthritis of large joints. Severe manifestations, threatening quality of life and even life itself, are the gastrointestinal manifestations which often perforate, arterial, mainly pulmonary arterial aneurysms which cause life-threatening bleeding, CNS manifestations and ocular disease, which with occlusive retinal vasculitis often leads to blindness. For milder manifestations low-dose steroids and colchicine are used, for moderate manifestations such as arthritis or ocular disease not immediately threatening visual acuity, azathioprin or cyclosporin A are combined with steroids. For severe manifestations, interferon-alpha, TNF-antagonists or cytotoxic drugs are recommended. Interleukin 1 (IL-1) antagonists are currently being examined in clinical studies.