Background Performing a nasopharyngectomy via a transoral approach has been reported; however, defining landmarks to facilitate this approach has not been addressed. This study aims to explore anatomical landmarks to aid in performing a nasopharyngectomy via the transoral corridor. Methods An endoscopic transoral nasopharyngectomy was performed on six cadaveric specimens (12 sides). Related anatomical landmarks were defined, and the strategy to preserve the parapharyngeal internal carotid artery (pICA) was explored. Results An endoscopic transoral nasopharyngectomy was successfully achieved in all 12 sides. Utilizing the pterygoid hamulus as a landmark, the cartilaginous ET and attachments could be adequately exposed. Identification of the pICA is a prerequisite prior to Eustachian tube (ET) transection. The sphenoidal spine and the petrotympanic fissure could be sufficiently revealed in all 12 sides, which aided in transection of the cartilaginous ET without pICA injury. The ET and the prevertebral contents could be adequately removed via the transoral corridor. Conclusion The pterygoid hamulus, sphenoidal spine and petrotympanic fissure serve as reliable landmarks for performing a transoral nasopharyngectomy. Identification of the pICA is a prerequisite prior to transection of the ET to avoid pICA injury.