Fifty-eight evaluable patients with non-Hodgkin's lymphoma were treated with a low dose, 120-hour continuous intravenous infusion of bleomycin in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone. Pharmacokinetic data, obtained in six patients, confirm that steady-state plasma concentrations of bleomycin can be attained even with the administration of 2 units/day of the drug. Neither clinical pulmonary toxicity nor subclinical pulmonary changes, as determined by serial measurement of the single breath carbon monoxide-diffusing capacity, were observed. Compared to similar chemotherapeutic programs utilizing bolus administration of bleomycin, pulmonary toxicity may be reduced. Response frequencies among 37 previously untreated patients were similar to those obtained using the same chemotherapeutic agents but with intravenous bolus administration of bleomycin. In addition, 18 of 21 patients who had received prior chemotherapy responded. Low dose, continuous intravenous infusion of bleomycin may improve the therapeutic index of combination chemotherapy programs for non-Hodgkin's lymphoma.