Background: The aim of this study was to investigate therapeutic outcomes and assess factors associated with therapeutic outcomes in hematologic patients with invasive pulmonary aspergillosis (IPA). Methods: We analyzed all consecutive cases of IPA in adults with hematologic diseases from January 2008 to January 2009 at a Catholic Hematopoietic Stem Cell Transplantation (HSCT) Center in Seoul, Korea. Results: A total of 54 patients were identified. Underlying diseases were acute myelogenous leukemia (n=25), acute lymphoblastic leukemia (n=10), myelodysplastic syndrome (n=7), chronic myelogenous leukemia (n=3), multiple myeloma (n=3), severe aplastic anemia (n=2) and other hematologic diseases (n=4). Twenty six patients (48.2%) were assessed as having a favorable response, of which 16 patients (29.6%) showed complete response. Overall 12-week mortality and IPA attributable mortality were 38.9% (n=21) and 33.3% (n=18), respectively. In multivariate analysis, uncontrolled underlying disease (odds ratio [OR], 7.31; 95% confidence interval [CI], 1.49~35.94; p=0.014) was associated with an unfavorable response, and for 12-week mortality, uncontrolled underlying disease (OR, 11.79; 95% CI, 1.49~93.46; p=0.020) and hypoalbuminemia (OR, 9.89; 95% CI, 1.42~68.99; p=0.021) were significantly poor prognostic factors. Conclusion: IPA still remains as a poor therapeutic outcome, especially in patients with refractory hematologic diseases.