Eight patients with relapsed B-cell non-Hodgkin's lymphoma were treated with intensive chemoradiotherapy and reconstituted with autologous bone marrow rendered free of tumour cells by the B-cell-specific monoclonal antibody anti-B1 and complement. Before the autologous marrow transplantation patients were induced with chemotherapy, radiotherapy, or both, into a minimum disease state with less than 5% bone-marrow involvement with tumour. All patients treated achieved a complete clinical response and had stable haematological engraftment by 8 weeks. No significant acute or chronic toxic effects have occurred. B cells could be detected by 2 months after transplantation and normal immunoglobulin levels were achieved by 6 months. Six of eight patients are disease free in unmaintained remission more than 20, 19, 10, 8, 5, and 3 months after transplantation.