In this prospective study, we evaluated 350 cases which were diagnosed as palpable or non-palpable lesions in the breast. Both core biopsy and FNAB were applied to all lesions. We compared the pathologic results of the two methods between the years 1997-2002. Fine needle aspiration biopsy and core biopsy are the most common percutaneous breast biopsy techniques in recent years. Both techniques have replaced surgical biopsies widely because of their high accuracy rate. However it is possible to achieve more successful results and decrease number of repeated biopsies. That’s why performance of both FNAB and core biopsy simultaneously will decrease disadvantages of both techniques and also will increase accuracy rates.