The clinical outcome of 23 patients with high grade diffuse large cell immunoblastic lymphoma (Working Formulation, category H) treated by an intensive shortened schedule regimen of chemotherapy is described. Alternating cycles of cyclophosphamide, doxorubicin, vincristine, bleomycin and prednisolone, and ifosfamide, etoposide and methotrexate were given over an 18-week (range 16.0-20.8) period. External beam radiotherapy was administered as consolidation therapy to sites of original bulky disease in 17 patients. Treatment was well tolerated, though there were two toxic deaths. A 90% response rate was obtained. Sixteen of 18 patients followed for a minimum of 36 months are alive and in complete remission, representing a disease free survival of 69.5%; two further patients are alive following autologous bone marrow transplant. The 3-year disease free survival was 73% (+/- 9%) and the overall 3-year survival 78% (+/- 9%).