Between 1970 and 1978 33 children with Non-Hodgkin-lymphomas at the age of 2-15 years were treated at the university children's hospital of Jena. 27 patients showed the first appearance of the disease, 6 patients had already been treated in other hospitals and were admitted with relapses. The biopsy material was classified or re-classified after the Kiel-classification. Beside the histological classification the surface markers of the malignant cells of NHL-patients were determined. 20 of 33 children were already in stage IV (Ann-Arbor-classification). Among our patients were 6 lymphoblastic NHL of Brukitt type, 10 of the convoluted cell type and 16 unclassified and one lymphoblastic lymphoma. The main localization of the NHL were mediastinum [15] and the gastrointestinal tract [10]. The therapy consisted of irradiation and chemotherapy (2 protocols) and, in case of an abdominal localization, in the attempt at a radical operation. Patients of stage I and stage II showed a complete remission rate of 50 per cent for 3 years; patients of stages III and IV of 20 per cent only. NHL of the convoluted cell type and of the Burkitt-type proved to have worse three-year-remission rates (16 per cent and 27 per cent) than unclassified lymphoblastic NHL (42 per cent).