We report a 45-year-old woman admitted to our hospital due to fever, consciousness disturbance, and severe seizures. Based on her signs and symptoms and clinical course, a diagnosis of non-herpetic acute encephalitis was made. She received antibiotic drugs, acyclovir, gamma-globulin, and steroid pulse therapy (methylprednisolone 1 g/day, 3 days). The patient's signs, symptoms and severe seizure showed marked improvement, but she still showed monthly seizure attacks and both anterograde and retrograde amnesia Viral infection and autoimmune response after viral infection may have been involved in non-herpetic acute encephalitis in our patient. Recently, autoantibodies to GluRepsilon2 and VGKC were reported in cases of non-herpetic acute limbic encephalitis (NHALE). In our patient, we detected IgM type autoantibody to GluRdelta2 and epsilon2 in both the CSF and serum, and these antibodies normalized in the CSF with the clinical course. Autoantibodies to GluRdelta2 and epsilon2 may be involved in the clinical symptoms and pathogenesis of non herpetic acute limbic encephalitis. This is the first report of MRI-positive non-herpetic acute encephalitis with autoantibodies to GluRdelta2 and epsilon2.