Stereotaxic fine-needle aspiration biopsy (SFNAB) was performed to evaluate suspicious mammographic findings (31 stellate lesions, 20 regions of grouped calcifications, two nodules, and one area of prominent trabecular markings) in 54 patients who had undergone reduction mammaplasty. SFNAB findings were correlated with findings in histologic specimens whenever possible; the cytologic samples were classified as malignant, atypical, or benign. In 22 lesions, the abnormalities on mammograms were considered highly suspicious for malignancy. In the 32 others, the degree of suspicion was lower, but these lesions had a change in appearance since acquisition of the first postoperative mammogram. SFNAB enabled diagnosis of adenocarcinoma in five women. Patients who have undergone mastectomy with reconstruction of one breast and mammaplasty in the other are at higher risk for development of contralateral breast cancer, as are all patients who have had such cancer. SFNAB is reliable for evaluation of suspicious mammographic abnormalities that develop after mammaplasty and findings that change after acquisition of the first postoperative mammogram.