Purpose: Patients with non-Hodgkin's lymphoma who fail to achieve a complete remission or who relapse are rarely cured with conventional therapies. For this group of patients, intensive therapy and bone marrow rescue may be curative. Our goal was to assess the effects of autologous transplantation in patients with B-cell lymphomas and a poor prognosis. To avoid occult or overt contamination with lymphoma, monoclonal antibodies BA-1, BA-2, and BA-3 were used for ex vivo marrow treatment. Patients and methods: Seventeen patients underwent intensive therapy and autologous bone marrow transplant using the forementioned marrow. Ten of the 17 patients (Group I) had disease that was in complete or partial remission. The other seven patients either had disease that was not responsive to treatment or had bone marrow transplant as their initial therapy at relapse. Results: The ex vivo treatment did not adversely affect engraftment. For those patients who could be evaluated, the median time to white cell engraftment was 24 days; the median durations of red cell and platelet support were 24 and 29 days, respectively. Eleven of the 17 patients had complete remissions at the evaluation 28 days after transplant. Three patients subsequently experienced a relapse, three died while their disease was in complete remission, and five are alive and disease-free 405 to 1,674 days after transplant. Group I patients had an estimated 40 percent disease-free survival rate at three years compared with 0 percent for Group II patients (p < 0.01). Conclusion: Our data support autologous bone marrow transplantation as an important treatment modality for the non-Hodgkin's lymphomas. With the current preparative regimens available, however, its use should be limited to patients with disease that is still responding to conventional therapies.