Glial fibrillary acidic protein (GFAP) astrocytopathy is a novel autoimmune meningoencephalomyelitis. Case 1 is a 26 years old (yo) woman with a bilateral ovarian teratoma. She presented neck stiffness, hyperreflexia, bilateral postural tremor and urinary retention. Three courses of a methylprednisolone pulse and subsequent enucleation of the bilateral ovarian teratoma improved her neurological symptoms with no recurrence. Case 2 is a 46 yo man who showed infectious-like symptoms with elevated creatine kinase. Case 3 is a 76 yo man with preceding weight loss, a hyperintensity lesion in the hypothalamus, and increased uptake of the spinal cord, assessed by Fluorine18 fluorodeoxyglucose positron emission tomography (18F-FDG PET). We compared the clinical features of the present three cases with previous reports. Consciousness disturbance, neck stiffness, tremors, and urinary dysfunction, were observed in all three cases. These findings suggest widespread damage of the brain and spinal cord.