Considering Aspergillus sp has remained the most common fungal isolate in AA patients for the past 20 years, it is only rational that an antifungal agent with broad spectrum, covering both yeast and fungi, be used in this context. Posaconazole, a triazole antifungal agent, not only has a broad coverage spectrum but also associated with predictable and reliable systemic bioavailability. Also for patients, once daily dosage is both pragmatic and convenient. According to meta-analyses of prophylactic antifungal agents use (published in 2007), fluconazole diminished the risk of fungal related mortality compared to placebo (RR 0.49, 95% CI: 0.32-0.75, P=0.0009). More importantly, when compared to fluconazole, posaconazole prophylaxis yielded even lesser fungal related mortality and significantly decreased invasive fungal infection rate. Considering the fact that posaconazole is already being used for acute myeloid leukemia (AML) and myelodysplastic syndromes patients undergoing induction treatment, it is only natural that posaconazole be used for AA/hMDS patients, who are at higher risk of developing invasive fungal infection compared to AML.