The relative benefit of allogeneic bone marrow transplantation (alloBMT) vs autologous BMT (autoBMT) for patients with relapsed or refractory Hodgkin's disease (HD) or non-Hodgkin's lymphoma (NHL) remains uncertain. Toxicity from graft-versus-host disease (GVHD) may diminish the potential benefits both of graft-versus-tumor activity and of receiving uncontaminated donor marrow stem cells. From 1987 to 1995, 27 adults (ages 18-60 years; median 36) underwent alloBMT for lymphoma after failure of standard chemotherapy. Twenty-one had NHL and six had HD (nodular sclerosis). Thirteen patients had primary refractory disease or chemotherapy-resistant relapses; two of these had relapsed after autoBMT. Three patients had untested relapses (one of them had relapsed after autoBMT), and 11 had chemotherapy-sensitive relapses. Twenty-four received HLA-matched bone marrow from a sibling (one twin); three received haploidentical marrow cells. Nine (33%) died from lymphoma. Eleven (41%) died of treatment-related causes. Opportunistic infections were a substantial problem leading to eight of these deaths (30%). Six patients (22%) survive free of lymphoma 17-70 months post-BMT (median, 56 months); four had had sensitive relapses, one had had a resistant relapse, and one had had nontested relapse. Three have chronic GVHD (limited in one; extensive in two). One HD patient who had relapsed after autoBMT remains in remission 19 months after alloBMT. No therapy-related myelodysplasia has been observed. We conclude that alloBMT has substantial morbidity in heavily pretreated lymphoma patients due to acute toxicity, infections and GVHD. However, 22% of our HD/NHL patients have had long-term disease-free survival.