Mucormycosis is an opportunistic infection with an acute onset, aggressive and often fatal course, especially seen in poorly controlled diabetic patients and in immunocompromised patients. Early diagnosis and treatment are very important. Treatment of the underlying predisposing factors in addition to the aggressive surgical debridement of infected tissues and appropriate antifungal therapy are recommended. Here, we report on a patient with diabetic ketoacidosis and rhino-orbito-cerebral mucormycosis who presented with fever, headache and exophthalmos. The patient was treated with surgical debridement, amphotericin B and posaconazole.