PURPOSE: A total thyroidectomy for the treatment of bilateral thyroid benign nodules is still controversial. This study prospectively compared the prognosis and complications of a total thyroidectomy with those after a subtotal thyroidectomy. METHODS: Between September 2003 and October 2006, a total of 110 consecutive patients with bilateral thyroid benign nodules underwent either a total (n=77) or subtotal thyroidectomy (n=33). Temporary or permanent hypoparathyroidism, temporary or permanent recurrent laryngeal nerve palsy, operation time, the length of hospital stay, postoperative thyroxine dosage in both operation groups were compared. In addition, the detection rate of a malignancy through a permanent biopsy was examined. RESULTS: There was a higher rate of temporary hypoparathyroidism, longer length of hospital stay and higher thyroxine dosage needed in the total thyroidectomy group than in the subtotal thyroidectomy group. There were no significant differences in the permanent hypoparathyroidism, temporary or permanent recurrent laryngeal nerve palsy and operation time between the two groups. The histopathological diagnosis was a malignant tumor in 13 patients. CONCLUSION: This study suggests that a total thyroidecotmy can be performed without increasing risk of complications. A total thyroidectomy avoids recurrent nodules for the removal of the whole thyroid tissue, which avoids the need for secondary surgery with an increased risk of complications when compared with primary thyroid surgery. A total thyroidecotmy is considered the first choice for the management of bilateral thyroid benign nodules.