Subacute sclerosing panencephalitis is a manifestation of persistent measles virus infection in the brain. It affects about 1/10 000 children who experience natural measles infection, but the risk is about 10 times higher if measles infection occurs below 1 year of age. Recent measles epidemics in central Europe will bring the possibility of this complication into consideration in the future. The diagnosis of subacute sclerosing panencephalitis should be considered in a child, adolescent or young adult with behavioral changes, myoclonia, forgetfulness, or deterioration of cognitive functions developing over weeks or months. Electroencephalogram is typical and measles antibody titers in the cerebrospinal fluid are diagnostic. Treatment includes immunomodulatory and antiviral agents, but results in relative remission or stabilization in less than 30% of patients. The fact that spontaneous remissions are also observed suggests host immunity as the main factor affecting outcome, therefore, supportive care and immunomodulatory agents constitute principal aspects of treatment.