Large core biopsy is a recently introduced method for pre-operative evaluation of breast lumps. The aim of this study was to evaluate the usefulness of this technique in providing pre-operative diagnostic and prognostic information that can lead to a correct line of treatment. We compared 41 cases of breast carcinomas diagnosed both by core biopsies and surgically removed samples. A high (93%) diagnostic agreement was obtained. Moreover, we found a significant correlation for mitotic count (r = 0.76), oestrogen receptor (r = 0.78), progesterone receptor (r = 0.80), p53 (r = 0.86) and c-erbB-2 (r = 0.90) analysis between core biopsy and definitive surgical pathology. An agreement for histological grading evaluation between the two techniques was obtained in 32 out of 40 cases (k = 0.65) whereas in the other cases, a lower grade was assigned by evaluating core biopsies. These findings suggest that percutaneous core breast biopsy is a valid tool for pre-operative management of breast lesions, but this should be confirmed in larger, prospective studies.