Vasculitis is a process caused by inflammation and necrosis of blood vessel walls and results in a variety of disorders. An accepted classification system for vasculitis is categorized by the size or type of the involved blood vessel as large-, medium-, or small-vessel vasculitis. Small-vessel vasculitis is defined as vasculitis that affects vessels smaller than arteries (i.e., arterioles, venules, and capillaries); however, small-vessel vasculitis can also involve medium-sized arteries. Granulomatosis with polyangiitis, Microscopoc polyangiitis, Churg Strauss syndrome and Renal Limited Vasculitis where the kidney is the only organ involved are clasified as a small vesselvasculitis. These disorders are described to be commonly associated with antineutrophil cytoplasm antibodies (ANCA). The etiology is not known and the incidence of vasculitis is incresasing occuring more often in elderly population. These diseases can cause the focal necrotizing lesions witch affect vessels and organs. In the lung it may cause alveolar hemorrhage, in the kidneys crescentic glomerulonephritis with acute renal failure, in the skin purpuric rash and ulcerations. Treatment usually includes corticosteroids, immunosupresive therapy and in some cases plasmapheresis. Advances in clinical management have been achieved during the past few years.