We retrospectively evaluated preoperative film- and xeromammography of 23 cases with breast cancers, and compared with postoperative specimen radiography to assess tumor delineation and microcalcification detectability. In tumor detection and margin delineation, film mammography was superior to xeromammography, and in microcalcification, film mammography was equal to xeromammography. These results had a effect on the diagnosis of breast cancers.