Abstract Abstract 4106 Background: Treatment of refractory or relapsed non-Hodgkin lymphoma (NHL) remains challenging. Here, 88 patients with refractory or relapsed NHL received treosulfan and fludarabine as a reduced intensity conditioning for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Material and Methods: 73/88 intensely pre-treated patients experienced a relapse (R) with 18/88 early relapses (ER < 6 months from the last chemotherapy). At the time of allo-HSCT, 26 patients were in complete (CR) and 43 in partial remission (PR), twelve patients had progressive disease (PD) and seven stable disease (SD). 47 patients received an autologous graft followed by allo-HSCT. Results: After allo-HSCT, 69 of 88 patients were in CR, seven patients in PR, resulting in an overall response rate of 86.4% (76/88). Thirty-three patients achieved a CR from PR as well as six patients from PD and five from SD. 43/88 (49 %) patients were alive at the end of follow-up. Patients undergoing directly allo-HSCT without preceding auto-HSCT showed a better disease-free survival (DFS, p =.038) with a trend (p =.077) for better overall survival (OS). Patients with ER showed an OS of.35 ±.12 after three and seven years. Chronic graft-versus-host disease (cGvHD) had a positive impact on both OS and DFS (for limited cGVHD versus no cGvHD p =.002 and.004, respectively). Conclusion: Allogeneic stem cell transplantation following conditioning with treosulfan and fludarabine constitutes a good therapeutical option for patients with refractory or relapsed NHL and should be considered early in the course of salvage treatment. Disclosures: Schmitt: Medac: Participation in Conferences. Sayer:Medac: Travel grant to ASH 2009. Koenigsmann:Medac: Research Funding. Casper:Medac: Participation in Conferences. Beelen:Medac: Participation in Conferences. Freund:Medac: Honoraria, Research Funding.