Six patients with advanced Hodgkin's disease in which multiple conventional treatments (median prior chemotherapy regimens: seven), radiation therapy, and a prior autologous stem cell transplantation (SCT) had failed underwent allogeneic SCT following a fludarabine-based conditioning regimen. Median age was 29 years (22-30). Median time to progression after autologous SCT was 6 months (4-21). Disease status at transplant was refractory relapse (n = 3) and sensitive relapse (n = 3). Cell source was filgrastim-mobilized peripheral blood stem cells from an HLA-identical sibling (n = 4) or matched unrelated donor marrow (n = 2). Conditioning regimens were fludarabine-cyclophosphamide-antithymocyte globulin (n = 4), fludarabine-melphalan (n = 1) and fludarabine-cytarabine-idarubicin (n = 1). Myeloid recovery was prompt, with an absolute neutrophil count > or =500/microl on day 12 (11-15). Median platelet recovery to > or =20000/microl was on day 9 (0-60). Chimerism studies on day 30 indicated 100% donor-derived hematopoiesis in 4/5 evaluable patients (4/4 non-progressors). All responders (3/3) have ongoing 100% donor-derived chimerism. Acute graft-versus-host disease (GVHD) was diagnosed in 4/6 evaluable patients. Chronic GVHD was present in 2/4 evaluable patients. There were no regimen-related deaths. Overall day 100 transplant-related mortality was 2/6 (33%). Three patients have expired and three are alive and progression-free with a median follow-up of 9 months (6-26) post transplant. We conclude that allogeneic stem cell transplantation with fludarabine-based preparative regimens is feasible in these high-risk, heavily pretreated HD patients.