Invasive fungal infections (IFIs) are a significant cause of morbidity and mortality for immunocompromised patients. Unfortunately, the clinical usefulness of many antifungal agents is limited by safety and tolerability. Posaconazole is a relatively safe and well-tolerated broad-spectrum azole antifungal agent. Newer posaconazole formulations, oral tablet and intravenous, increase its availability to a larger patient population.