From literature review concerning diagnosis and management of isolated sphenoid fungal sinusitis we found that this isolated lesion is extremely rare especially in immunocompetent patients; it is frequently difficult to diagnose, as patients present with nonspecific symptoms such as headach, visual disturbance and cranial nerve palsies. Diagnosis of the disease is typically not made until advanced imaging has been developed. We presented a case of isolated fungal sinusitis of left sphenoid sinus with headach and diplopia, treated by endoscopic sphenoidotomy with the help of the navigation system, after which recovery was full.