Recent development of mammographic stereotactic localization devices has created considerable interest in the possibility of fine-needle aspiration biopsy (FNAB) of non-palpable breast lesions. The results of FNAB performed during the course of 50 breast lesion localizations were evaluated. The authors compared two methods of lesion localization, one using a standard mammographic unit and localization technique and the other a stereotactic unit and localization technique. The results of FNAB were similar regardless of technique. With all inadequate specimens considered benign, sensitivity, specificity, and diagnostic accuracy for the standard technique were 71%, 100%, and 93%, respectively, and for the stereotactic technique, 80%, 100%, and 95%. Although these results are preliminary and the number of cases is small, the findings suggest that needle placement for FNAB with the standard localization technique may be as accurate as that with the stereotactic technique.