In immunocompetent patients the postnatally acquired toxoplasmosis is usually a mild or asymptomatic disease. CNS manifestations are rare, e.g. in patients with HIV infection or in patients with other types of immunosuppression. We report on a 9-year old healthy boy, who was hospitalized after one week with subfebrile temperatures and headache with clinical signs of encephalitis and unilateral deafness. We diagnosed a toxoplasmosis and treated the patient with pyrimethamine and sulfadiazine. While most of the signs and symptoms disappeared rapidly the deafness persisted.