Abstract Ameloblastoma is a locally aggressive tumor derived from odontogenic epithelium. Although benign, its clinical behavior may often times exhibit malignant characteristics. It is marked by slow and persistent growth with infiltration of adjacent tissues. Almost 70% occur in the mandible in patients over 30 years of age. Recurrence of ameloblastoma due to inadequate treatment is frequent. Due to its slow growth, recurrences may present decades after primary surgery. A primary ameloblastoma in an area outside of the mandible, maxilla and infratemporal fossa regions has not been described in detail to date, with only one possible case mentioned in literature. The authors present a case of primary temporal bone ameloblastoma in a 17-year-old male patient. The tumor originated in the left mastoid, infiltrating the lateral semicircular canal, facial nerve and cochlea, adhering to the sigmoid sinus and posterior cranial fossa dura. Although invasion of multiple structures in the infratemporal fossa and the temporal bone leads to variable disease presentation, this case is unique when considering that the first symptom of disease was unilateral recurring sensorineural sudden hearing loss. S urgery required transection of the facial nerve. Histopathology confirmed primary temporal bone ameloblastoma. The difficulties in achieving wide surgical margins, diagnostics and further management are also addressed.