Forty-six previously untreated patients with advanced aggressive non-Hodgkin's (34 poorly differentiated and mixed diffuse, 8 histiocytic and 4 undifferentiated) were treated with a 3 phase combined modality program employing cyclophosphamide (C), hydroxyl-daunomycin (H), vincristine (O), prednisone (P), procarbazine (P) [CHOP(P)] combination chemotherapy in an initial induction phase, radiotherapy and nonmarrow toxic chemotherapy as a second consolidation phase, followed by a third phase of CHOP(P) chemotherapy for four more cycles. Long-term maintenance therapy was not given. High dose involved field radiation in phase II was limited to volumes encompasing less than 50% of the marrow bearing skeleton. The large majority of patients (82%) had such widespread involvement that this limitation precluded the use of local radiation and were treated instead with a mean of 132 rad of fractionated total body irradiation (TBI). Thirty-eight patients (83%) achieved complete remission. Twenty-nine (66%) of the 44 patients evaluable for follow-up, and 22 (61%) of the 36 patients receiving TBI, remain alive in complete remission for observation periods of up to 26 months.