OBJECTIVES This study conducted the cost minimization analysis (CMA) of Posaconazole compared with currently licensed antifungal agents including Voriconazole (IV and oral), Caspofungin, and L-AMB in the treatment of confirmed infection of invasive aspergillosis with refractory disease in Korea. METHODS Through a systematic review of preceding literature, we firstly figure out the factors that determine clinical success and clinical failure for each of the comparators and secondly investigate whether Posaconazole decreases infectious morbidity and mortality of the patients from RCTs with various conditions. Without clinical or observational dataset of Posaconazole and other comparators of the treatment for Korean patients, this study indirectly adopted the determinants and probabilities from the clinical results in all languages to decision tree model for antifungal treatment to estimate the clinical outcomes, and conducted the probabilistic sensitivity analysis and economic analysis. This study also estimated the direct costs associated with invasive aspergillosis treatment. RESULTS For the antifungal treatment, the study showed that Posaconazole incurs smaller drug costs than Voriconazole depending upon the almost similar effectiveness between the two AF agents. Based on the desired drug price of Posaconazole (€61.90/400mg) and average KRW-Euro exchange rate in 2008, the result showed that incremental cost of KRW6,934,591 (€4,387.30) would be saved compared with the expected drug cost of Voriconazole, Caspofungin, and L-AMB based upon their market shares. CONCLUSIONS Probabilistic analysis on net monetary benefit showed that invasive aspergillosis treatment with Posaconazole is cost-saving method in Korea compared to Voriconazole and other licensed antifungal agents.