Sixth cranial nerve palsy is the most frequent of the oculomotor palsies and may result from diverse etiologies, including intracranial or nasopharyngeal tumors. We report the case of a 36-year-old man in whom sixth nerve palsy was the initial manifestation of an undifferentiated carcinoma of the nasopharynx (UCNT). This case highlights the importance of ophthalmologic signs as a potential clue for early diagnosis of nasopharyngeal carcinoma.