BACKGROUND: The extent of thyroid surgery in Graves' disease is still controversial. Resistance to the more widespread use of a total thyroidectomy has been based on the misbelief that an increased complication rate is inherent in its use, despite the potential advantage in terms of reduced rate for recurrence of hyperthyroidism, cure of probable malignancy, and possible ablation of underlying autoantibodies from the residual thyroid tissue. We tried to determine the safety and the usefulness of a total thyroidectomy for the treatment of Graves' disease. METHODS: We retrospectively compared the outcomes of patients who underwent a total thyroidectomy with those of fifteen patients who underwent a subtotal thyroidectomy for Graves' disease. Six patients were treated by using a total thyroidectomy in five years' time for Graves' disease or for recurrence of hyperthyroidism after the use of antithyroid drugs. Surgical complications, recurrence of hyperthyroidism, occurrence of thyroid cancer, and serum levels of T3, T4, and TSH receptor antibodies were evaluated. RESULTS: Until now, there has been no evidence of a higher complication rate in a total thyroidectomy than in a subtotal thyroidectomy, with regards to recurrent hyperthyroidism, vocal cord palsy, and perma nent hypocalcemia. There was only a tendency for a higher rate of temporary hypoparathyroidism in total thyroidectomy patients. Different from the total thyroidectomy group, one patient with recurrent hyperthyroidism and one patient with a thyroid malignancy which was found in the residual tissue after a subtotal thyroidectomy required further operations. The improvement rate of ophthalmopathy was higher in the total thyroidectomy group than in the subtotal thyroidectomy group (60% vs. 22%). CONCLUSION: A total thyroidectomy for Graves' disease may be an effective and safe therapy. At least, it does not present more complications then a subtotal thyroidectomy if it is done meticulously by an experienced endocrine surgeon. However, it can avoid worsening of the thyroid humoral autoim munity, relapse of hyperthyroidism, and occurrence of a hidden malignancy. We suggest that a totalthyroidectomy may be considered as the operative treatment of choice for Graves' disease, especially in the case of severe ophthalmopathy or of highly probable malignancy in the near future.