Many information concerning orbital complications of sinus diseases has been published, but reports on optic neuropathy secondary to isolated sphenoid sinus Aspergillosis is extremely rare, which may occur via direct spread of invasive disease or through communicating veins despite intact sinus walls. Optic neuritis is generally defined as an inflammatory neuropathy of the optic nerve usually associated with infectious, inflammatory, compressive, neoplastic or vascular processes. We recently experienced one case of optic neuritis secondary to sphenoid sinus Aspergillosis. A 60-year-old woman with decreased visual acuity and headache was admitted to the Department of Neurology. Suspicious isolated sphenoid lesion on CT and MRI was removed by endoscopic sphenoidotomy. Fungal ball in the right sphenoid sinus was found. On follow up, a recurred fungal ball was noted in the same sphenoid sinus and removed by endoscopic surgery. Adjuvant antifungal chemotherapy was tried but discontinued due to severe side effect. The patient recovered from fungal sinusitis but visual disturbance was unchanged.