The aim of the present study was to assess the appropriateness and value of prophylactic thyroxine therapy in the treatment of postoperative complications (relapse, postoperative hypothyroidism) following subtotal thyroidectomy for endemic goiter. The study was carried out in a group of 139 patients undergoing subtotal thyroidectomy for endemic goiter between 1978 and 1987. Clinical follow-up included hematochemical and scintigraphic analyses. Patients were divided into two groups. The first group included 74 patients who received postoperative hormone replacement therapy. The second group of 65 patients did not receive any treatment. results show that hormone replacement therapy is unnecessary in most cases since the majority of patients require euthyroid values a few months after operation. Thyroxine therapy was indicated, however, in cases of clinically evident postoperative hypothyroidism which persisted during follow-up.