Inflammatory rheumatological diseases are immunologically characterized by a break in tolerance to the body's own structures and by uncontrolled inflammation. Vasculitides are a heterogeneous group of autoimmune and inflammatory diseases characterized by inflammation of the blood vessels. These diseases often take an organ- or life-threatening course. Changes in the innate and adaptive immune system are the pathophysiological basis for the development of vasculitis. Increasing insight into the immunological basis of this group of diseases has allowed the development of effective, targeted therapies in recent years.