In this article, three systemic vasculitides--polyarteritis nodosa, microscopic polyangiitis, and Churg-Strauss syndrome--are reviewed, focusing on advances in the understanding of the pathogenesis, new classification nomenclature, and major clinical features of these vasculitides. Distinguishing criteria between polyarteritis nodosa and microscopic polyangiitis are also presented in detail, and recent advances in the clinical management of these diseases according to appropriate therapeutic strategies are recommended.