We report the clinical and neuroimaging findings of patients with glial fibrillary acidic protein (GFAP)-immunoglobulin G (IgG)-like anti-astrocytic antibodies in their cerebrospinal fluid. We identified 28 patients whose IgG reacted with astrocytes in a tissue-based assay but did not react with GFAPα in a cell-based assay. Many patients presented with fever and/or headache, followed by consciousness disturbance, meningeal irritation, hyperreflexia, and urinary disturbance. Three patients each showed perivascular radial gadolinium enhancement or longitudinally extensive spinal cord lesions on magnetic resonance imaging. Thirteen of 14 patients responded to the immunotherapies. We suggest that these patients exhibited immunotherapy-responsive inflammatory neurological disorders with cerebrospinal fluid GFAP-IgG-like anti-astrocytic antibodies.