Seventy previously untreated patients with stage II, III, and IV intermediate- or high-grade lymphoma were treated with methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B) between September 1985 and November 1987. Forty-nine of these patients had diffuse large-cell lymphoma (DLCL), and eight of these patients were human immunodeficiency virus (HIV)-positive. Complete responses were achieved in 54% of all patients and 52% of those with DLCL. With follow-up extending to 36 months, 45% of all DLCL patients are alive, and 50% are still living, if the HIV-positive patients are excluded from the analysis. Chemotherapy was quite toxic. Seventy-five percent of patients had severe mucositis, 42% had peripheral neuropathy, 50% required hospitalization, and 54% experienced leukopenia with a WBC count below 1,000/microL. Seven percent (five patients) died of toxicity related to the chemotherapy. Our analysis of prognostic parameters indicated that B symptoms, a performance status below 80, and, to a lesser extent, elevation of serum lactic acid dehydrogenase (LDH) (in HIV-negative DLCL patients) were associated with an inferior survival. Advanced age, sex, and bulky disease were not found to have a statistically significant effect on survival. Our preliminary results indicate that MACOP-B chemotherapy is an effective regimen for high- and intermediate-grade lymphomas. However, the survival for patients with DLCL treated with MACOP-B is no different than that achieved with previous regimens at our institution.