Posaconazole is an antifungal medication used primarily to treat invasive fungal infections caused by various organisms, such as Aspergillus, Candida, and certain molds. It belongs to the class of drugs known as triazole antifungals. Clinical studies have reported posaconazole to be effective in treating various invasive fungal infections, especially in patients who are immunocompromised, such as those with weakened immune systems due to conditions like HIV/AIDS, undergoing chemotherapy, or having received an organ transplant. It has effectively treated invasive candidiasis, aspergillosis, zygomycosis, and other serious fungal infections. The effectiveness of the drug varies based on factors, such as the type of infection, the patient's immune status, and the site of infection. This review describes the types of infection, the drug's safety profile, the development of resistance to posaconazole, and strategies to manage or prevent resistance.