Following the limited success of T-cell depletion in patients undergoing allogeneic bone marrow transplantation (BMT), recent interest is focused on autologous BMT. The selection of sensitive methods for detecting residual lymphoid malignancy, the choice of very efficient complement-fixing lytic monoclonal antibodies against residual disease, and the "tailoring" of these antibodies (or their cocktails) to individual patients lead to a very high remission rate in acute lymphoid leukaemia (ALL) of bad prognosis and second remission. The future of this extension of chemotherapy toward BMT seems to be promising, but controlled trials are required to show that the purging of bone marrow contributes to this good result. Very efficient antibodies for elimination of B lymphoma cells are also available.