Twenty-five children undergoing surgery for thyroid carcinoma, were compared in a retrospective study. Clinical characteristics and disease course were detailed in three groups. In the first of 11 patients, a lobo-isthmusectomy was performed for a thyroid nodule, except two cases of total thyroidectomy (TT). Papillary carcinoma was diagnosed on histologic findings. Preoperative cytology and peroperative frozen section examination were inadequate for diagnosis. All children had a complete remission after treatment. In the second group, 10 children had evident thyroid carcinoma with cervical lymph node metastases, and lung metastases in two. Microscopicaly, there were diffuse sclerosing variant or multifocal papillary carcinoma. A TT with central node dissection was performed in all, with a lateral lymph node dissection in 9. Treatment included radioiodine therapy and thyroxin suppression therapy. Three patients had a postoperative recurrent laryngeal palsy, one hypoparathyroidism. Reoperation was carried out in 4 for cervicomediastinal lymph node recurrence. All patients are alive, with a complete remission, except for the two patients with lung metastases. In this group of aggressive tumors, a complete cure was possible with combination of extended, sometimes repeated, surgery and radioiodine therapy. In the last group, 4 patients had a medullary carcinoma. One presented with a thyroid nodule. The others were asymptomatic with a positive pentagastrin test during biological screening for familial disease. Two patients with lymph node metastases had a persistent pathologic calcitonin test despite a TT with complete central and lateral lymph node dissection. Early genetic screening in family members is the only way to perform a curative thyroidectomy in a prepathologic stage.