The term anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) covers a group of rare diseases with inflammation in the small vessels and associated with the presence of ANCA. The patients can present with signs and symptoms from almost all organs. In primary care as well as in hospitals AAV is important to acknowledge as differential diagnosis to cancer and infectious diseases, because low morbidity and mortality related to AAV is dependent on early diagnosis and timely treatment. Patients suspected of AAV should be finally diagnosed and treated at specialized centres.