OBJECTIVE: Thyroglossal duct cyst (TGDC) carcinoma is a rare entity and its management is controversial. The aim of this retrospective study was to: (a) identify patients with TGDC carcinoma followed up in our clinic and (b) study specific characteristics of the disease and their association with thyroid carcinoma. DESIGN: Medical files of patients with TGDC carcinoma were reviewed and tumour characteristics, lymph node metastases, treatment and follow-up were evaluated. RESULTS: A total of 6 patients, 4 females and 2 males, mean age 39.3 years (median 33.5), were treated for papillary thyroid carcinoma arising in a TGDC carcinoma of the thyroid gland was found simultaneously in 4 of these patients, while in one patient thyroid carcinoma developed 10 years after the diagnosis of TGDC carcinoma. A variable clinical picture and presentation was recorded. The most aggressive manifestation of the disease in terms of local infiltration, local recurrence and lymph node metastases was observed in our youngest patients. CONCLUSIONS: Long-term follow-up is necessary for patients with thyroid carcinoma arising in a TGDC. In view of the frequent co-existence of thyroid cancer in these patients, we would recommend detailed thyroid evaluation and, eventually, total thyroidectomy at initial diagnosis of TGDC carcinoma.