The results of a chemotherapy regimen utilizing adriamycin in combination with vincristine, prednisone plus or minus cyclophosphamide (CHOP-HOP) for the treatment of non-Hodgkin lymphoma are compared to those of a non-adriamycin containing combination (COP). The complete remission (CR) rate of 67% for CHOP-HOP in malignant lymphoma, diffuse histiocytic type (MLDH) is superior to 33% obtained with COP. In malignant lymphoma, nodular poorly differentiated lymphocytic (MLNPD), the CR rate was: CHOP-HOP 83%, COP 44%. The prognostic factors for both treatment groups were compared and found to be similar. Thus, adriamycin appears to be responsible for this improvement in CR rate. When analyzed as a group, the patients treated with CHOP-HOP had a longer survival than those treated with COP. This difference was also evident in the subgroup of patients with MLDH. The smaller subgroup of patients with MLNPD treated with CHOP-HOP did not show a significant improvement in survival. A trend for longer duration of CR in both diffuse and nodular lymphomas was also observed, but this difference did not reach statistical significance possibly due to the smaller numbers of patients. Combination chemotherapy with adriamycin has resulted in a higher CR rate and survival for patients with non-Hodgkin lymphoma particularly for the subgroup of patients with MLDH.