Posaconazole is a commonly used medication for antifungal prophylaxis in patients with high-risk acute leukemia, such as acute myeloid leukemia. Despite clinical data that show that posaconazole is superior to other antifungal prophylaxis medications, posaconazole is known to have many side effects and drug-drug interactions. We present a patient who developed rhabdomyolysis after being started on posaconazole for prophylaxis in the setting of relapsed acute myeloid leukemia.