From 1981 through 1988, 35 patients with prior augmentation mammoplasty were treated for breast carcinoma. Thirty-two patients had unilateral infiltrating carcinomas; three had noninvasive (in situ) lesions. Thirty-four of 35 (97%) lesions were palpable. One noninvasive cancer was occult, discovered mammographically in the absence of physical findings. Prebiopsy mammography was performed in 29 patients with palpable masses and failed to reveal an abnormality in 12 patients, a false-negative rate of 41%. Fifteen patients were treated with mastectomy; the remaining 20 with breast preservation. Thirty-two patients underwent axillary node dissection; 15 (47%) patients had lymph node metastases. There have been seven (20%) recurrences: one local and six metastatic. Four (11%) patients have died. The median follow-up time is 48 months. Women, previously augmented with silicone gel-filled implants, who develop breast cancer are similar in terms of nodal positivity and prognosis, to nonaugmented breast cancer patients who present with palpable masses. When compared with nonaugmented women whose cancers were found with screening mammography, augmented patients with breast cancer present with a higher percentage of invasive lesion and involved axillary lymph nodes, resulting in a poorer prognosis.