The aim of this work was to evaluate the accuracy of vacuum-assisted biopsy by comparing it with frozen biopsy. 141 stereotaxic biopsies were performed by Mammotome (Ethicon Endo-Surgery, Hamburg) from January 2000 to March 2001. Biopsies were performed for microcalcifications (n = 105, 74.5%), irregular opacities (n = 20, 14.2%), regular opacities (n = 6, 4.2%), stellate lesions (n = 10, 7.1%). Histological analysis showed 85 (60.3%) benign lesions, 46 (32.6%) malignant lesions including (21 cases of carcinoma in situ and 25 invasive carcinomas) and 10 (7.1%) atypical lesions. All malignant lesions were subjected to surgery. In three cases (1 in situ and 2 invasive), core biopsy was excisional and no residual lesion was observed. Two of the carcinomas in situ revealed invasive features on the surgical biopsy. One of the atypical lesions was underestimated and the final diagnosis was "well differentiated carcinoma in situ." Only three of benign lesions underwent surgery after Mammotome biopsy. Among the 55 frozen-section biopsies of mammographically detected breast lesions performed in the same period, were one false-positive and 3 false-negative cases, while in 4 cases the diagnosis was deferred after paraffin embedding. Our results confirmed Mammotome biopsy as an effective alternative and a more reliable method than frozen-section examination.