Purpose: The aim of this study was evaluate predictive value of preoperative sonography for the evaluation of axillary lymph node metastases in breast cancer patients. Materials and Methods: The study included 226 patients who underwent curative surgery between Jan. 2008 Dec. 2010 at Inje University Sanggye Paik Hospital. We analyzed preoperative sonographic findings of axillary lymph nodes and compared the finding with postoperative histologic results of axillary lymph nodes evaluation. Results: When we compared preoperative sonographic evaluation of metastatic lymph node with final histological results, the sensitivity of sonographic evaluation was 81.3% and specificity was 77.5%. False positive rate was 10.7% and false negative rate was 35.8%. The accuracy of preoperative sonographic evaluation of lymph node metastasis was 78.7%. Primary tumor size was the only significant predictive factor for lymph node metastasis on multivariate analysis. Conclusion: preoperative sonographic evaluation of axillary lymph node had limited value with moderate accuracy. High false-negative rate of preoperative sonography indicates that preoperative sonography cannot replace intraoperative sentinel node evaluation at this stage.