Iodine-induced thyrotoxicosis (IIT), due to iodine application in high amounts in patients with circumscript or disseminated thyroid autonomy, is complicated by a prolonged course, mainly due on the body's resistance to conservative therapy with thiourea derivates. Therefore, we decided to perform subtotal thyroidectomy in 16 thyrotoxic patients. This is in contrast to the common opinion that surgery should only be performed after normalization of thyroid hormones. In all 16 patients with severe IIT, including three patients with thyroid storm, hormone levels decreased within a few days after surgery to normal or subnormal values and the clinical picture of thyrotoxicosis disappeared. In the case of thyroid storm the signs of disorientation normalized within 1-3 days. One patient died 5 weeks after surgery due to severe concomitant diseases. One patient exhibited transitory respiration distress and another had postoperative hypocalcaemia. In nine patients L-thyroxine replacement became necessary because of subclinical or clinical hypothyroidism. Only by this procedure will the high intrathyroidal storage of iodine and performed hormone be extracted. Surgery as a treatment for thyrotoxicosis should be reserved for patients with severe IIT, where conservative treatment has been shown to be ineffective. Furthermore, in rare selected cases, when a rapid normalization is required, surgery without preoperative treatment seems to be justified. The effect of surgery was impressive in all our cases and there were only minor perioperative complications. Thus, it could be shown that subtotal thyroidectomy may be a rational and effective treatment in severe IIT which should be carefully considered and weighed against other types of therapy.