The authors report 6 cases of acute encephalopathy during the course of primary rubella infection. The mean age of the patients was 7 years and 6 months. Clinical features included, 3 days after an inconstant exanthema, seizures, coma and hyperthermia. The diagnosis of rubella was confirmed by a high rate of antibodies in serum with presence of IgM fraction. Five children recovered fully, one patient remained epileptic. The authors discuss the problems of diagnosis, the nosological position and the treatment of non-congenital rubella encephalitis.