In the past decade, primary and secondary central nervous system (CNS) vasculitides have been more commonly diagnosed and recognized than previously. With the increasing awareness of these disorders, it is crucial for the treating physician to differentiate between causes of CNS vasculitis and to recognize their marked clinical and pathophysiological heterogeneity. This review focuses on the major forms of primary CNS vasculitis, as well as secondary CNS vasculitis with emphasis on their clinical findings, diagnoses, and treatment.The proposal of reversible cerebral vasoconstriction syndromes (RCVS) as a unifying concept for a group of disorders which are characterized by acute-onset severe recurrent headaches, with or without additional neurologic signs and symptoms, and prolonged but reversible vasoconstriction of the cerebral arteries, has been a major breakthrough in this field over the past decade. Recognition of this common mimic (i.e. RCVS) has allowed optimal management of a sizable group of patients previously confused with pathologically documented CNS vasculitis.Sound treatment decisions are based on accurate diagnosis. It is essential for the clinicians involved in the evaluation of patients with CNS vasculitis to be aware of its mimics especially RCVS. This article provides a comprehensive review of CNS vasculitis and its differential diagnosis. Furthermore, it touches upon workup and treatment of CNS vasculitis.