We report a 25-year-old female who developed clinical and electroencephalographic (EEG) features of subacute sclerosing panencephalitis (SSPE) at the age of 17 years. After almost 17 months of progressive neurological deterioration to a level where she was bedridden and incapable of self-care (Risk and Haddad stage 3a), she experienced a substantial spontaneous clinical and EEG remission (stage 4c) which she has maintained for the last 8 years. The measles antibody titer in the cerebrospinal fluid (CSF), however, progressively increased during follow-up. There are only very few patients with well documented diagnosis of SSPE who have maintained such a prolonged remission. The age at onset of SSPE of > or = 12 years, disappearance of periodic complexes and a tendency for normalization of the background activity in the EEG, and a progressive increase in the measles antibody titer in the CSF appears to predict a favourable outcome of SSPE.