Miliary lung metastasis is well known in thyroid carcinoma. However, thyroid carcinoma itself is very rare inchildren. We have seen a case of papillary adenocarcinoma of the thyroid in a 12-year old boy. He had extensivenodular lung metastases on the chest X-ray, which were confirmed by 131-I scintigraphy and biopsy of a cervicallymph node. Radioactive iodine therapy was instituted for 5 years and nodular lung metastases effectivelydisappeared on the follow-up chest x-rays. A lung scintigraphy with 131-I, however, showed residual uptake in thelung suggesting that scintigraphy is more sensitive and, therfore useful for evaluating the management of thethyroid carcinoma.