Rhinocerebral mucormycosis is a rapidly progressive and often fatal infection frequently seen in patients with uncontrolled diabetes mellitus and hematologic malignancies. The disease is difficult to diagnose because it often masquerades as bacterial sinusitis. The current report describes a 69-year-old white woman with diabetes mellitus who was prescribed high-dose prednisone therapy for chronic obstructive pulmonary disease. Two weeks after treatment initiation, she presented to the hospital with facial edema on the right side, mouth pain, and general weakness. No black eschars on the nasal mucosae or palates were present on admission. Although bacterial etiology was initially suspected, surgery and tissue samples revealed the presence of rhinocerebral mucormycosis. The patient died at 6 days postadmission despite aggressive medical and surgical intervention. The current report discusses the risk factors associated with rhinocerebral mucormycosis as well as the necessity of early diagnosis and treatment to improve patient outcomes.