AIM: The objective of this study is to determine the optimal surgical approach for patients undergoing thyroid operation for indeterminate follicular lesions diagnosed by cytology and to evaluate the long-term outcome of patients treated by hemi or total thyroidectomy for these lesions. MATERIAL OF STUDY: From January 2000 to January 2010, 98 patients having a solitary thyroid nodule with a cytological diagnosis of “indeterminate follicular lesion” were selected retrospectively. RESULTS: There were 81 women and 17 men with a mean age of 56 years (range: 28-83). Hemithyroidectomy (HT) was performed in 57 patients (58%) and a Total thyroidectomy (TT) in 41 (42%). Postoperative morbidity was 3.50% in patients who underwent HT and 9.75% in those who underwent TT. At the histological analysis 16 (16.32%) patients had a malignant lesion. DISCUSSION: HT was considered adequate treatment for 51 patients (89.48%) while in 6 patients (10.52%) has been necessary a completion thyroidectomy. Total thyroidectomy was not associated with clinically significant additive morbidity. No permanent hypoparathyroidism and no definitive recurrent nerve palsies were observed in either group. Postoperative thyroid hormone replacement was required in 40.35% of lobectomy patients. Overall, in the indeterminate follicular lesions patient population, 57 hemithyroidectomies were performed and no further operation was required in about 90% of patients. CONCLUSIONS: Considering the high rate in which HT represents the adequate treatment, and the low rate of re-operation morbidity, HT seems to be the preferable initial surgical approach for indeterminate follicular lesions. Long-term ultrasonographic follow-up seems advisable.