The vasculitides are a collection of diseases sharing the central feature of tissue injury due to inflammation of blood vessels. Although some occur frequently, many are encountered uncommonly or rarely. Nonetheless, because peripheral or central nervous system abnormalities may be a prominent part of these disorders, neurologists should know or be able to refer to studies on the classification, pathophysiology, treatments, and long-term complications of vasculitis. Two central issues that confront us now are 1) improving the accuracy of diagnosis, including identifying any underlying infectious causes, and 2) limiting the long-term damage from both the disease and its therapies.