Thirty-six children and adolescents were treated for carcinoma of the thyroid gland over a 30-year period. The average age at the time of histological diagnosis was 11.8 years. Seventeen patients (47%) gave a history of previous exposure to ionizing radiation for benign disorders in the head and neck area. Two patients died from neoplasm. The longest period of survival has been 26 years after diagnosis. Twenty-six carcinomas were a mixed papillary and follicular type, 5 were pure papillary, and 5 were wholly follicular. Thirty-two patients had regional lymph node metastases. Nine patients had roentgenographic evidence of pulmonary metastases. Two of this group died; of the remaining 7 patients, all but 1 have had complete resolution after administration of radioactive iodine. This study supports the impression of an increasing incidence of thyroid carcinoma, which may be related to exposure to previous irradiation.