Mucormycosis is a rare, potentially fatal and opportunistic infection caused by fungi belonging to the order Mucorales. Rhinocerebral, gastrointestinal, pulmonary, cutaneous and disseminated are the different forms of mucormycosis. Rhinocerebral mucormycosis is the most common type and presents as a highly destructive infection in immunocompromised hosts, especially in patients with poorly controlled diabetes. The infection originates in the nasal mucosa owing to fungal inoculation and then spreads to the paranasal sinuses, orbits, orbital apex, cavernous sinuses and brain. Our patient was a 36-year-old female with poorly controlled diabetes who presented with orbital symptoms and signs, with very subtle involvement of the sinuses. She had stenosis of the entire left internal carotid artery, with multiple small infarcts in the left frontal and parietal lobes. She incidentally had tooth caries tooth with a periapical cyst and an oroantral fistula. Ours was a histopathologically proven case of rhino-orbito-cerebral mucormycosis.