Summary:A total of 40 patients with relapsed/refractory Hodgkin's disease (HD) underwent reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) from an HLA-identical sibling (n ¼ 20) or a matched unrelated donor (n ¼ 20). The median age was 31 years (range 18-58). Disease status at allo-SCT was refractory relapse (n ¼ 14) or sensitive relapse (n ¼ 26). The conditioning regimens were fludarabine-cyclophosphamide7antithymocyte globulin (n ¼ 14), a less intensive regimen, and fludarabinemelphalan (FM) (n ¼ 26), a more intensive one. The two groups had similar prognostic factors. The median time to neutrophil recovery (ie absolute neutrophil count X500/ll) was 12 days (range 10-24). The median time to platelet recovery (ie platelet count X20 000/ll) was 17 days (range 7-132). Day 100 and cumulative (18-month) transplantrelated mortalities (TRMs) were 5 and 22%. Twenty-four patients (60%) are alive (14 in complete remission or complete remission, unconfirmed/uncertain) with a median follow-up of 13 months (4-78). In all, 16 patients expired (TRM n ¼ 8, disease progression n ¼ 8). FM patients had better overall survival (73 vs 39% at 18 months; P ¼ 0.03), and a trend towards better progression-free survival (37 vs 21% at 18 months; P ¼ 0.2). RIC allo-SCT is feasible in relapsed/refractory HD patients with a low TRM. The intensity of the preparative regimen affects survival. Bone Marrow Transplantation (2005) 35, 943-951.