Background/purpose: Patients with acute leukemia undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) are exposed to high risk of developing invasive fungal infections, and the invasive mold infections (IMIs) are becoming more and more common after transplantation. Here, we conducted a retrospective study to analyze demographics, microbiology, and risk factors for IMIs development in adult acute leukemia patients undergoing allo-HSCT. Methods: We reviewed 245 adult acute leukemia patients undergoing allo-HSCT from January 2003 to December 2014. Clinical characteristics including age, sex, conditioning regimens, European Group for Blood and Bone marrow Transplantation (EBMT) risk score, and presence of acute graft-versus-host disease (aGVHD) or chronic GVHD (cGVHD) were collected and analyzed. Cox proportional hazard model was adopted to explore the independent risk factors for IMIs developments. Results: Seventeen of 245 patients developed IMIs during the study period. The cumulative incidence of IMIs in this cohort was 8.7% and 16.8% at 6 and 12 months, respectively, with Aspergillus species being the most common pathogen. The significant risk factors predicting IMIs were unrelated donor transplantation (hazard ratio [HR] 5.11), smoking (HR 3.55), EBMT risk score > 2 (HR 4.22), and moderate to severe cGVHD (HR 3.76). Conclusions: We identified four risk factors-unrelated donor transplantation, smoking, EBMT risk score >2 and moderate to severe cGVHD to predict IMIs among acute leukemia patients undergoing allo-HSCT. This cohort study suggests early identification of high-risk patients and to provide better prevention strategies would reduce the incidence and severity of IMIs in these patients. Keywords: Acute leukemia, Allogeneic hematopoietic stem cell transplantation, Mold infection, Graft-versus-host disease, Smoking