One hundred and eleven consecutive patients with highgrade non-Hodgkin's lymphoma treated in three centres between 1983 and 1988 were analysed to assess the efficacy of different types of chemotherapy. The median age at presentation was 56.9 +/- 16.6 years. According to the Kiel classification histological subtypes were: centroblastoma (n = 45), immunoblastoma (n = 17), lymphoblastoma (n = 6), T cell lymphoblastoma (n = 9), histiocytoma (n = 2), and high grade unclassified (n = 32). Patients were clinically staged, 68 patients (61%) belong to stage I-II. and 43 had widespread disease (stage III-IV.). Remission was achieved in 81 cases [70 complete (CR) and 11 partial (PR) remission], 30 patients did not respond. The most effective modality of treatment was extended field irradiation completed with chemotherapy (81% CR, 7-year overall survival 65%) followed by ProMACE-COPP chemotherapy (67% CR, 4-year survival 40%) and CHOP-Bleo chemotherapy (65% CR, 7-year survival 25%). Age and histological subtype had no prognostic relevance, whereas clinical stage proved to have significant influence on remission and survival.