Rhino-orbital-cerebral mucormycosis is a severe and rapidly progressive fungal infection associated with low survival rates. Early diagnosis and proper management are mandatory. We report the case of a 20-year-old female with diabetic ketoacidosis and teeth infection, who presented with sudden orbital apex syndrome. Several surgical procedures were necessary to provide a definite histopathological diagnosis of the fungal infection. Ultimately, given the progressive aggravation of the infection and the ineffectiveness of antifungal and antibiotic agents, an orbital exenteration was performed. A mycobacteriological examination revealed a polymicrobial culture with Mucorales. One year after the initial presentation, the patient is alive and with a good general health condition.