The search for a satisfactory medical treatment of thyrotoxicosis to overcome the limitations of surgical treatment continues. Potassium perchlorate has been shown to displace iodine from the thyroid gland. This appears to be the first report of the use of potassium perchlorate in juvenile thyrotoxicosis. Six girls from 6
to 13 years of age were controlled with potassium perchlorate. No side-effects were observed. Details are given in the case reports for periods of observation extending up to 3 years. Simplicity and economy are advantages of this form of therapy, which appears to deserve further trial.