We report eight patients with adult-onset subacute sclerosing panencephalitis (SSPE), of which, four were treated with oral isoprinosine and four with intraventricular alpha-interferon plus oral isoprinosine. One of the four patients treated with oral isoprinosine died within two months, and the disease progressed in three patients. Of the four patients treated with oral isoprinosine plus intraventricular alpha-interferon, one showed mild progression, one remission, and the remaining two showed stabilization. The group of patients is relatively small, but our results suggest that treatment with oral isoprinosine plus alpha-interferon is effective for SSPE.