Aberrant internal carotid artery in the middle ear (aICA) is a rare congenital malformation in which the internal carotid artery passes through the tympanic cavity without being separated by bone. A pulsatile vascular mass can be observed in the tympanic cavity of patients with aICA. The diagnosis of aICA may be challenging because improper surgery or treatment can lead to iatrogenic injury, including massive hemorrhage. The aim of this case report was to describe a 39-year-old woman with aICA presenting with mixed hearing loss and postauricular pain. We provided detailed clinical images of the patient to illustrate how aICA can be diagnosed. Because this patient’s aICA had no risk of bleeding, close observation, pharmacological therapy, and regular follow-up were applied. The patient’s postauricular pain was significantly improved after treatment with oxcarbazepine. At the time of this manuscript’s preparation, the patient had been monitored for 10 years and had stable mixed hearing loss with no other complications. Based on the management of this patient, oxcarbazepine can improve aICA-associated postauricular pain, and conservative treatment should be prioritized in cases of aICA without a risk of bleeding. Further studies in a large cohort are required to confirm our findings and recommendations.