PURPOSE: Percutaneous vacuum-assisted breast biopsy (Mammotome, Fa. Ethicon Endo-Surgery Breast Care) is now commonly performed as the initial approach to diagnose and treat benign breast lesions. It can obviate the need for surgery in women with benign lesions and often lead to a one-stage surgical procedure when malignant lesions are diagnosed. The purpose of this study was to report the outcome of the Mammotome biopsy.. METHODS: We performed 902 cases of Mammotome biopsy (total 474 patients) to confirm the diagnosis and to excise the lesion between January 2003 and December 2006. Among all these cases, 888 cases with radiographically suspected benign lesions, below BI-RADS category 4, were followed up for more than 6 months and we analyzed clinical and pathologic results of these cases, retrospectively. Ultrasonographic follow-up examinations were performed and no malignant tumor or atypical ductal hyperplasia was included. RESULTS: The mean patient age was 42 (range: 17~76) years. The average size of lesion was 1.12 (range: 0.20~5.0) cm. In BI-RADS category, there were 450 (49.8%) C2 lesions, 158 (17.8%) C3 lesions and 251 (27.8%) C4 lesions. Histology revealed 506 cases (56.0%) of fibrocystic disease, 295 (32.7%) fibroadenomas, 11 (1.1%) intraductal papillomas, 16 cases (1.7%) of sclerosing adenosis, 21 cases (2.5%) of ductal epithelial hyperplasia, 18 cases (2.1%) of fat necrosis, 3 cases (0.3%) of gynecomastia, 18 cases (1.9%) of chronic inflammation. 824 lesions (92.8%) were completely removed, 39 cases (4.4%) of residual lesion and 25 cases (2.8%) of postoperative scar were reported. CONCLUSION: Mammotome biopsy is an effective diagnostic and therapeutic management of benign breast lesions with minimal-invasiveness and minimizes postoperative complications.