This paper presents a case of dizziness caused by a cyst in the parapharyngeal space. The patient was a 25-year-old woman who visited us with chief complaints of a sore throat, nausea and dizziness. The cervical CT showed a large cyst in parapharyngeal space. Pathologically, the cyst was diagnosed to be branchial cleft cyst. Dizziness appeared in suspending and rotating head positions. As to its etiology, it was considered that the cyst presses the sympathetic plexus surrounding the internal carotid artery in parapharyngeal space to cause sympathetic functional disturbances of the inner ear on extension of the neck.
