Isolated sphenoid pathology is uncommon. Nasal polyps that originate from the anterior wall of the sphenoid sinus and reach the nasopharynx are called sphenochoanal polyps. The atypical location of sphenochoanal polyps leads to misdiagnosis, and surgery risks injuring the surrounding structures, such as the optic nerve, carotid artery, and brain. For the differential diagnosis of sphenochoanal polyps, nasal endoscopy and computed tomography are very important. We present the clinical and radiological features of a sphenochoanal polyp and review the status of the optic nerve during endoscopic surgery for a sphenochoanal polyp.