BACKGROUND: Immune checkpoint inhibitors (ICI) represent an important new class of immunotherapy used in cancer treatment. Though effective, immune-related adverse events (irAE) are reported, including cerebral vasculitis (nirVasculitis). In this systematic review, we aim to identify clinical and laboratory features of nirVasculitis and exemplify these in six local clinical cases. OBSERVATIONS: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two independent researchers searched, identified, and extracted data from both PubMed and Embase to identify reports on nirVasculitis. Based on current criteria for diagnostic certainty patients were categorized as having definite, probable, or possible nirVasculitis. 20 cases described relevant symptomatology and met our inclusion criteria. Non-small-cell lung cancer (55%) was the most frequent cancer type. Most cases (95%) received a programmed death-1 (PD-1) inhibitor. One patient had definite vasculitis, seven probable vasculitis, and twelve possible vasculitis. Signs and symptoms included aphasia (n=5), loss of consciousness (n=7), confusion (n=8), unilateral sensory or motor dysfunction (n=5), and fever or headache (n=9). All patients had brain imaging and seventeen underwent a lumbar puncture. Of these, 64.7% had pleocytosis and 52.9% elevated protein in cerebrospinal fluid. Nineteen patients received corticosteroids. Eight patients fully or partially recovered. Eight patients died due to nirVasculitis, three to advanced cancer, and one lost to follow-up. CONCLUSIONS: There are few clinical reports of nirVasculitis which may be due to underreporting or rarity of complications. Guidelines for diagnostics and reporting may improve awareness and early recognition to initiate important immunosuppressive treatment.