Persistence of the underlying malignancy remains the major obstacle limiting the success of high-dose chemoradiotherapy with autologous bone marrow transplantation (BMT) for non-Hodgkin's lymphomas. We used the 38C13 murine B-cell lymphoma model to explore the approach of transferring tumor antigen-specific immunity with syngeneic BM as a protective element. Mice serving as syngeneic marrow donors were twice immunized with tumor-derived surface Ig protein, the idiotype of which serves as a tumor-specific antigen, or with a control Ig of matched isotype. Naive lethally irradiated recipients reconstituted with marrow from immune donors showed serologic tumor idiotype-specific immunity, as well as protection against lethal tumor challenge. The immunoprotective effect of immune marrow was also shown in lethally irradiated recipients partially protected by specific immunization post-BMT. Combined donor and recipient immunization also replaced the requirement for the booster immunization of the donor. These results provide the rationale for active immunization with purified surface Ig from autologous tumor as an adjunct to autologous BMT in humans.