Background and Objective：A post-operative hypertrophic scar of the anterior neck is the leading complaint of the patients who underwent conventional thyroid surgery. In order to minimize the post-operative scar of the anterior neck, we performed thyroidectomy via axillary approach using operating microscope and a specialized retractor to determine technical feasibility. Patients and Methods：From January 2005 to December 2006, we performed thyroidectomy via axillary approach under operating microscope(f=400mm, ${ imes}2.5$；OPMI $pico^{(R)}$；Zeiss, Germany) for benign unilateral nodule in 25 cases(all female, average age 34.5yrs). Under general anesthesia less than 7cm of skin incision was made in the axilla of ipsilateral side. A subcutaneous tunnel went over the pectoralis major muscle and the clavicle, and then through the sternocleidomastoid muscle and sternothyroid muscle was excised. The area around the thyroid was sufficiently dissected, and then a retractor designed for exposure via axillary approach was placed within the tunnel and under operating microscope thyroidectomy was performed. Results：There were 17 cases of thyroid nodulectomy and 8 cases of subtotal lobectomy. The mean average operative time was 102.64minutes. Postoperative complications included one case of postoperative bleeding, one case of temporary vocal cord paralysis, two cases of delayed wound healing, two cases of paresthesia of shoulder and arm, and two cases of hypertrophic scar of the axilla. Postoperative histopathology includes 17 cases of adenomatous hyperplasia, six cases of cyst, and two cases of follicular adenoma. For all cases hospitalization period was two days. Conclusion：Thyroidectomy via axillary approach under operating microscope has a good cosmetic advantage without a post-operative scar of the anterior neck. The procedure is simple due to direct vision using operating microscope, easy to identify important structures by magnifying them, and therefore surgical time can be reduced.