Rubella is usually encountered as a mild viral illness in children and complications are not common. We reported rubella encephalitis in the atypical course of rubella without rash in a 9-year-old boy. He was admitted with a headache, fever, loss of consciousness and bilateral retroauricular lymphadenopathy. The cerebrospinal fluid (CSF) examination showed lymphocytic pleocytosis, increased protein levels and a normal glucose value. Immunoglobulin (Ig) M antibodies against rubella virus were positive in CSF and serum. IgG antibody also became positive in his serum 3 weeks after his admittance. We emphasized that rubella may appear without any rash and cause encephalitis. In unvaccinated children, rubella should be considered in the differential diagnosis of encephalitis.