Objective: To describe clinical presentation, preoperative study, intervention, histology, surgical complications and follow-up characteristics, and survival in patients with thyroid carcinoma (TC) with less than 18 years at presentation., Material and Methods: retrospective analysis of clinical data of all children and adolescents followed in S. João Hospital from January 1, 2000 to March 31, 2010 with histologic diagnosis of TC., Results: Twenty-three patients were identified, 19 girls, and 4 boys. Median age at presentation was 17.0 years. Annual incidence was 2.3 cases/year. The main presenting symptom was a solitary thyroid nodule (60.8%). Three (13%) patients had risk factors for TC, 2 of the 3 had previous cervical irradiation. The other was a smoker. Total thyroidectomy was performed in 16 (69.6%), and 10 patients underwent a second surgical procedure. Four (17.4%) patients had postoperative complications. Histologic examination revealed differentiated TC in all, papillary thyroid carcinoma (PTC) in 86.9%, follicular carcinoma in the remaining. All patients received thyroxine suppressive therapy and 20 underwent therapeutic radioactive iodine (131I). During follow-up (7.1 years), 7 out of the 23 patients presented new metastases and needed new treatment. All patients are currently alive., Conclusions: TC is a reality in pediatric population, thyroid routine examination should take part in all clinical examination in children and adolescents., (Copyright © 2011 SEEN. Published by Elsevier Espana. All rights reserved.)