Invasive aspergillosis (IA) is a major cause of morbidity in patients with hematological malignancies, and a major impediment to the success of allogeneic stem cell transplant (allo-SCT). The aim of this single-center retrospective study was to determine the impact of pre-transplant IA on the outcome of allo-SCT after reduced-intensity conditioning (RIC). Twenty-eight cases of proven or probable IA were diagnosed prior to RIC allo-SCT at the Paoli-Calmettes Institute Cancer Center between January 2000 and January 2008. These cases were identified among 360 patients undergoing allo-SCT. IA was defined according to EORTC criteria. Patients had predominantly (82%) acute myeloid leukemia, were diagnosed with IA at a median of 8 months (range, 1-16) pre-transplant, and received antifungal therapy for a median of 5 months (range, 1-13). IA therapy included: voriconazole (71%); single-agent itraconazole (14%); and a combination of agents (14%). Secondary prophylaxis against aspergillosis was maintained during conditioning and post-transplant in 89% of patients. After transplant, only three patients (11%) had reactivation of their IA and one patient developed disseminated fusariosis. The latter four patients experienced severe acute GVHD treated with high-dose corticosteroids. None of these patients died of IA. Eighteen patients (64%) are still alive, with a median follow-up of 23.5 months (range, 12.6-48.5). Overall survival at 2 years was 59% (95% CI, 43-83%). These data suggest that patients with adequately controlled IA can tolerate RIC allo-SCT without significant post-transplant complications.