We report a case of a 54-year-old patient, an unbalanced diabetic, who presented rhino-orbito-cerebral mucormycosis with orbital involvement as circumstance of discovery. The aims are to highlight the importance of making an early diagnosis to improve prognosis of this infectious pathology. Early diagnosis requires clinical suspicion of infection in all immunocompromised patients, particularly in diabetics with ketoacidosis and clinical research of typical necrotic plaques on the eyelid, palate or sinus level.  Histopathological analysis makes diagnosis. Angiography-MRA and angiography-CT scan remain complementary examinations to assess the extension and guide treatment. The management must be multidisciplinary. Association of intravenous antifungal treatment (especially amphotericin B) and localized or radical surgical debridement is the treatment of choice. Local treatment with amphotericin B  increases tissue penetration.