Garcin syndrome is characterized by progressive unilateral multiple cranial nerve palsy without the presence of intracranial hypertension. In this case, we present a patient who experienced lower cranial nerve (CN 9–12) involvement attributed to post-mucormycosis osteomyelitis of the skull base. The osteomyelitis resulting from mucormycosis led to the development of Garcin syndrome, which manifested as progressive paralysis of the cranial nerves. It is important to recognize this rare complication and consider it in the differential diagnosis when evaluating patients with lower cranial nerve palsy following mucormycosis-related skull base osteomyelitis.