We assessed the accuracy with which stereotactic core biopsy of breast microcalcifications helps to justify follow-up or indicate required surgical planning. Eighty-nine patients underwent stereotactic breast biopsy performed with large core needles. Histopathologic findings of microbiopsies were correlated with radiological findings, with follow up and with surgical findings. Agreement between radiological and histopathologic findings on biopsies was obtained in 86% for benign results. Even in the case of benign radiological findings, the histological results of microbiopsies required a surgical biopsy justified in 10% of cases. Radiologically suspicious or malignant microcalcifications were correlated with 35% benign and 65% malignant histologies on biopsies. The positive predictive value, negative predictive value and accuracy were respectively 93%, 86% and 95%. Invasive lesions were found on microbiopsies in 39% of excised malignant lesions. Multifocal lesions were proved on microbiopsies in 50% of all excised carcinomas. Microbiopsies help to disclose malignant lesions undetected on radiological analysis, and may obviate diagnostic surgical biopsy in many cases.