The place of allogeneic bone marrow transplantation (BMT) in the treatment of aggressive non-Hodgkin's lymphoma (NHL) remains controversial. We conducted a retrospective study of French experience in allografting NHL between 1984 and 1994. To improve the homogeneity of the study population, cases of low-grade, Burkitt and lymphoblastic NHL were excluded. 73 patients were included in the analysis. Median age at transplantation was 35 years (range 9-61 years); 64 patients were in stage IV and 45 had bone marrow involvement at diagnosis. At the time of transplantation, 46 patients had sensitive disease (25 in complete remission; CR). The overall survival (OS) and progression-free survival (PFS) rates were 41% and 40% respectively at 5 years (median follow-up of survivors 90 months). The probability of disease progression was 30% at 5 years, and only one relapse occurred after 15 months. 32 patients died of transplantation-related complications. In multivariate analysis, pretransplant complete remission was the main factor associated with longer survival (OS at 60 months of 76% among the 25 patients in CR at transplant and of 23% among the 48 patients not in CR at transplant). Neither acute nor chronic graft-versus-host disease (GvHD) influenced the relapse rate. In conclusion, in this high-risk population the overall results of allogeneic BMT were encouraging, despite a high transplant-related mortality rate. We believe this procedure should be studied further in prospective controlled trials.