Patients with chemorefractory aggressive non-Hodgkin's lymphomas (NHL) generally have poor clinical outcomes with available therapies. Allogeneic transplantation may be curative, but few studies are available to guide transplant decision making in this setting. We examined allogeneic transplantation outcomes for 46 patients with chemorefractory, aggressive NHL patients who had either stable disease (SD; n = 32) or progressive disease (PD; n = 14), respectively, following last salvage treatment. The median age was 46 years (range: 22-63 years). Thirty-nine patients received matched sibling allografts, whereas 7 underwent unrelated donor transplantation. Diagnoses included diffuse large B-cell lymphoma (n = 18), Burkitt's lymphoma (n = 3), transformed B cell lymphoma (n = 5), mantle cell lymphoma (n = 11), and peripheral T cell lymphoma (n = 9). The median number of prior therapies was 3 (range: 2-8). Median follow-up of surviving patients is 5 years. Five-year overall survival (OS), progression-free survival (PFS), and relapse rate for the whole cohort (n = 46) were 38%, 34%, and 35%, respectively. The rate of grade II-IV acute graft-versus-host disease (aGVHD) was 43%. Of the 33 evaluable patients 75% developed chronic GVHD (cGVHD). Overall nonrelapse mortality (NRM) rate was 34%. The 5-year OS and PFS rates for patients with SD and PD were 46% versus 21% (P = .01; log-rank test), and 46% versus 7% (P = .0002; log-rank test), respectively. This study confirms that allogeneic transplant is curative for a subset of chemorefractory patients with SD. However, patients with PD had uniformly poor outcomes following allografting with conventional conditioning approaches. Given the outcomes seen here in the setting of PD, such patients should proceed with transplant only in the setting of investigational therapy.