Dermoid cysts are benign developmental anomalies that occurred as a result of the sequestration of the skin along the lines of embryonic closure. Those occurring in the cervicofacial region are uncommon, accounting for about 7% of all dermoids and its presence in postauricular region is further exceptionally rare. A healthy 19-year-old Asian boy presented with a unilateral postauricular cyst that had been present since childhood without any symptom. The computed tomography scan revealed an encapsulated tumor with no intracranial extension. Histological examination of a biopsy taken from the lesion revealed a unilocular cyst found in the deep dermis and subcutaneous tissue. Multinuclear giant cells and fragments of hair shaft are infiltrated in the cystic wall. Some keratin materials are seen in the intracystic area. However, the lining cells are not found. These histologic findings were suggested of the dermoid cyst. Patients with postauricular dermoid cysts usually seek medical advice for the cosmetic reasons because of the embarrassing look of the prominent unilateral or bilateral ears. The treatment of postauricular dermoid cyst is complete surgical excision of the cyst wall. Incomplete removal may result in recurrence or infection; thus, complete surgical excision is necessary. The prognosis is excellent without further complication.