Cervical teratomas are rare neoplasms in adults. A 21-year-old male was admitted to our hospital for evaluation of a cervical tumor. CT scan and MRI showed the tumor extended into the mediastinum and not invaded to surrounding tissue. 201T1 scintigram showed increased uptake in the tumor. The tumor was resected with coller incision and median sternotomy. Histological examination revealed mature teratoma. The patient remains free of disease one year and seven months after operation.