Two patients with subacute sclerosing panencephalitis (SSPE) are described. They were diagnosed on admission to the hospital with SSPE, as judged on cerebrospinal fluid examination involving reverse transcription followed by polymerase chain reaction, at the second stage of Jabbour's classification. They first were treated with intraventricular interferon-alpha monotherapy; however, the combination of interferon-alpha and IV ribavirin was started at 8 and 5 months after beginning the interferon-alpha monotherapy, respectively. Although slow progressive brain atrophy was observed in Patient 1 on brain magnetic resonance imaging before the ribavirin therapy, no further progression was noted 11 months after starting combination therapy with ribavirin. The event-related potential study results and audiography of the right ear improved in Patient 1 after the combination therapy was initiated. In Patient 2 the hypertonicity, neurobladder incontinence, and dysphagia improved 3 months after starting the combination treatment. Although this group of patients is small, these results suggest treatment with intrathecal high-dose interferon-alpha and IV ribavirin is effective in the treatment of SSPE. Early administration of intrathecal high-dose interferon-alpha and IV ribavirin should be considered as a possible therapy for SSPE patients, especially interferon-nonresponding ones.