Seventeen patients with malignant lymphoma, including 13 with progressive disease and four in remission following primary chemotherapy, received high-dose chemotherapy, fractionated total-body irradiation (TBI), and allogeneic marrow transplants. Eleven of the 13 (85%) patients in relapse who received transplants achieved remission, and three remain disease free 41, 21, and 17 months later; one patient in second remission who received a transplant is disease free at 11 months. Thirteen patients are dead: four because of progressive lymphoma, seven because of interstitial pneumonitis, and two because of complications of severe acute graft-v-host disease. These results are similar to those noted in marrow transplantation series for advanced acute leukemia; since transplantation during remission has decreased relapse and improved survival in leukemia, earlier transplantation may produce improved results in lymphoma patients as well. However, the effectiveness of conventional therapy regimens for most lymphomas and the high incidence of severe transplant-related complications usually limit allogeneic transplantation to lymphoma patients in situations other than consolidation of first remission. Initial partial remission, early relapse from an initial remission, and perhaps second remission are situations in which conventional therapy is often ineffective, but the adverse features of very advanced lymphoma are not present; marrow transplantation may be considered in eligible patients. Transplant recipients with more advanced disease are anticipated to have poorer survivals.