Fifteen patients with augmentation mammoplasties had mammography demonstrating nonpalpable breast lesions. Of the 15 patients, three (20%) had adenocarcinoma confirmed by open biopsy and histopathology. All patients underwent stereotactic localization for fine needle aspiration biopsy. Four of the 15 patients had benign cysts (26%). None of the cysts could be diagnosed by ultrasound. The remaining eight patients had mammary dysplasia of a proliferative or nonproliferative type of fibroadenoma. These benign entities were followed with interval mammography demonstrating no change. The data suggest that fine needle aspiration biopsy is an effective technique to assess nonpalpable breast lesions in patients who have had augmentation mammoplasties.