Large-core needle biopsy (LCNB) has become a more widely used technique in the evaluation of breast lesions. This study was undertaken to access the accuracy of percutaneous LCNB on breast lesions and the impact on further proceeding.A retrospective review of imaging-guided LCNB of 159 breast lesions was done. 143 LCNB were taken with ultrasound guided automated spring gun biopsy and 16 stereotactic-guided with vacuum-assisted biopsy device. Histology and morphobiological parameters were compared with subsequent material from surgery.In 113 core biopsies (71%), an infiltrating breast cancer was diagnosed, 5 biopsies (3%) yielded in-situ/atypical lesions and a benign lesion was shown in 38 cases (24%). In 3 cases, insufficient/necrotic material was obtained. 108 patients underwent subsequent surgery. In 100/108 cases (93%), histology on LCNB and surgery was identical. LCNB was false negative in 5 core biopsies (5%). Immunhistochemical stains of hormone receptors, bcl-2, c-erbB-2, p53 and MIB-1 was comparable on LCNB and on surgical material. Based on the results of LCNB, 17/113 patients (15%) with infiltrating carcinoma were primarily treated with hormones or with neoadjuvant therapy. 32/38 patients (84%) with benign lesions were followed up by imaging control.In patients with benign lesions on imaging, open biopsies can be avoided by LCNB. In patients with biopsy proven carcinoma, therapy planning is improved. The addition of morphobiological parameters allows early individual treatment.