Thirty-five patients treated for 37 cases of breast cancer after augmentation mammaplasty were analyzed. All augmentations were performed with silicone gel prostheses at a mean age of 38 years (range 24 to 59 years). The mean interval from breast augmentation to the detection of breast cancer was 7.5 years. Physical examination demonstrated a palpable breast mass in 35 of the 37 cases (95 percent). The pathologic staging was in situ 3 (8 percent), local 18 (49 percent), and nonlocal 16 (43 percent). Standard compression mammography was performed in 31 patients prior to breast biopsy. Abnormalities were detected in 17 (54.8 percent). Palpable masses were visualized in only 12 (38.7 percent). Ultrasound was utilized successfully in 3 patients with palpable masses to guide fine-needle aspiration biopsy. Standard two-view mammography has a low sensitivity in detecting palpable cancers in patients who have undergone augmentation mammaplasty. Ultrasound should be evaluated as a routine adjunctive screening method in this group of patients. The clinical detection of breast cancer, as evidenced by pathologic staging, is not delayed.