A 10-year-old boy with subacute sclerosing panencephalitis was treated with intravenous gamma-globulin and inosiplex and followed for 18 months. Clinical improvement, demonstrated by decreasing scores on the Neurologic Disability Index, was observed. There were no side effects. We recommend intravenous immune globulin as an alternative therapy in the treatment of subacute sclerosing panencephalitis.