The diagnosis of ANCA-associated vasculitides (AAV) consists of clinical symptoms, results of technical procedures and a characteristic histology. The diagnostic workup should focus on the prominent clinical symptoms and should involve an interdisciplinary team of specialists. The therapy is divided into induction and maintenance treatment. Cyclophosphamid remains standard therapy for the induction of remission, whereas azathioprine, methotrexate and leflunomide are often used for maintenance therapy. The introduction of a stage-adapted treatment has contributed to a significant improvement of the long-time prognosis of patients with AAV.