BACKGROUND Tinnitus can be a symptom of a wide range of disorders. The identification and treatment of the underlying condition is essential for management of tinnitus in children. Tinnitus can occur with medical conditions other than sensorineural hearing loss. Cerebellopontine arachnoid cysts are rare and can cause tinnitus and hearing loss in adults. Tinnitus caused by an arachnoid cyst has not been reported in an adolescent. We report clinical and radiological features of a teenager with bothersome tinnitus caused by an arachnoid cyst. CASE REPORT A 14-year-old girl with unilateral tinnitus for 10 months presented to the Pediatric Otolaryngology Clinic. The loudness and duration of tinnitus had progressed gradually. Turning the head to the right induced right otalgia and tinnitus. The patient denied hearing loss, vertigo, exposure to loud noise, feeling of fullness in ear, otorrhea, facial weakness, numbness, dysphagia, changes in smell or taste, and problems with the jaw or temporomandibular joint. The focused neurological examination and head and neck examination were within normal limits. The patient had normal hearing on audiometry. T1-weighted, T2-spin-echo, T2-FLAIR, and diffusion-weighted magnetic resonance imaging sequences were obtained, revealing a right cerebellopontine angle arachnoid cyst. After arachnoid cyst marsupialization, the patient's tinnitus and otalgia resolved. CONCLUSIONS This case highlights the importance of suspecting identifiable nonauditory system disorders as causes of tinnitus in children. Thorough analysis of clinical findings and timely use of imaging is critical to prevent delay in diagnosis and treatment of children with bothersome tinnitus caused by rare medical conditions.