Hypothesis: Specimen mammography is not beneficial in the management or outcome of patients undergoing image-guided needle-localized breast biopsies. Design: A retrospective study of consecutive patients who underwent needle/dye-localized breast biopsies between January 1, 1993, and December 31, 1995. Setting: National Cancer institute (Bethesda, Md)designated comprehensive cancer center. Patients: One hundred sixty-four patients underwent 165 needle/dye-localized breast biopsies for suspicious mammographic abnormalities. Results: In only 3 (1.8%) of 165 patients did the patient clearly benefit from specimen mammography. In no patient was a malignant neoplasm missed. The mean time for the specimen mammogram was 20 minutes, adding an additional 55 hours of operating room time. Specimen mammography cost an additional $60522 and was incorrect in 41 (24.8%) of 165 patients. Conclusion: Specimen mammography added little to patient care, as only 3 (1.8%) of 165 patients benefited from the information.