With the ongoing economic development, lifestyle changes and an aging population, diabetes mellitus has be come one of the most prevalent chronic diseases in the world. Rhino-orbito-cerebral (ROC) mucormycosis is a rare, acute and angioinvasive fungal infection that can be fatal. Mucormycosis occurs exclusively in immunocompromised patients with diabetes mellitus and other types of immunodeficiency and has three subtypes: Rhino-maxillary, rhino-orbital and ROC mucormycosis. The present study reported on a case of ROC mucormycosis in a patient with diabetic ketoacidosis. In the present case, the pathogen afflicted all of the above organs, including the left eye, nasal cavity, hard palate and cerebrum.