Thyroglossal duct cyst(TGDC) is the most common midline congenital neck mass in children. However, carcinoma arising from TGDC is very rare and most of them are found in adults. In this report, we describe a 9-year-old child presenting with TGDC, which finally turned out to be papillary thyroid carcinoma. He underwent Sistrunk operation only. We review the literature and highlight the important points of the treatment.