Papillary thyroid carcinoma (PTC) arising from a thyroglossal duct cyst is very rare. PTC usually presents as a slow-growing, painless thyroid mass or a solitary nodule in the neck. We intend to report a rare case of 47 year old male, who presented with a progressively increasing midline neck swelling for the last 4 years. On examination, the mass was cystic without any solid nodule. No palpable neck nodes ware present. A clinical diagnosis of thyroglossal duct cyst was made. Ultrasonography showed a single large lobulated cystic mass, with foci of calcification. Sistrunk procedure was followed to excise the lesion. Histopathological examination of the excised mass showed variable sized thyroid follicles, areas of calcification and foci of atypical cells with features of papillary thyroid carcinoma. The patient was treated with 50 Gy of Co-60 radiotherapy and 6 cycles of adjuvant chemotherapy with Cisplatin 50mg/m2. He is doing well after 12 months of follow up period without any metastasis.