The total non-Hodgkin's lymphoma-population treated between 1978 and 1986 by means of radiotherapy or combined chemo/radiotherapy was analysed as to primary extranodular manifestation. 39 cases, 16 women and 23 men, were observed (stage IE 12, stage IIE 22 and stage IIIE 5). Immunoblastic (10), lymphoblastic (9) and centroblastic (6) lymphomas are the most frequent with respect to histology. Gastroenteron (16) and otorhinolaryngological region (13) are in the lead with regard to localisation. 5-year-survival-rates are determined in dependence on clinical stage: IE 65.8%, IIE 39.2% (low, connected with the proportion of high-malignant histology) and IIIE 25.0%. The 5-year-survival-rate of primary gastrointestinal manifestation amounted to 51.5%. With respect to aetiopathogenesis of primary extranodular lymphomas gut-, mucosa- and bronchial-associated lymphoid tissue, aberrant lymph-nodes and the influence of viral- and immunologic factors seem to be important.