This paper is dedicated to a general and synthetic review of a large and heterogeneous group of diseases, entitled "Systemic Vasculites". Despite its rarity in clinical practice, they can be severe and even fatal, if a proper diagnosis and adequate treatment is not made. Among the several classifications, we have adopted the Chapel Hill classification based on its pathogenesis. As they are multiple entities, we will describe only the essential clinical aspects of the diverse vasculitis, including the diagnostic criteria of the American College of Rheumatology, which are very sensitive and specific. We will conclude with a note on the global strategy of treatment of each entity.