Management of thyroid hormone ingestion is controversial. We present nine children with massive levothyroxine ingestion who experienced a benign course. Their serum thyroxine levels ranged from 19.9 to 84.7 micrograms/dl. Seven were clinically euthyroid, and the other two had mild symptoms. No specific therapy was given. We recommend gastrointestinal decontamination procedures and serum thyroxine levels for an ingestion of greater than 2.0 mg of levothyroxine (or its equivalent). If levothyroxine has been ingested, neither immediate hospitalization nor prophylactic antihyperthyroidism therapy is recommended. If the initial serum thyroxine level is significantly elevated, close outpatient follow-up, especially during days three to 10, is warranted. However, massive ingestion of thyroid extract or triiodothyronine may require immediate hospitalization for observation. Therapeutic interventions aimed at extracorporeal removal of excess thyroid hormones are not recommended. Specific antithyroid therapy should be reserved for those rare patients with significant symptoms of thyrotoxicosis.