The purpose of this study was to determine whether breast cancer patients who had prior breast augmentation presented at a more advanced stage than nonaugmented breast cancer patients, and to determine the mode of presentation and effectiveness of lymphatic mapping and sentinel lymph node biopsy in this same group of patients. A total of 4186 breast cancer patients from 1987 to 2002 were reviewed. Patients who had augmentation before their diagnosis of breast cancer were compared with a control group of nonaugmented breast cancer patients. The Wilcoxon rank sum test was used to compare tumor size, node positivity, and stage. The patient’s age at presentation was also compared by the two-sided pooled t test. Seventy-six patients who previously underwent augmentation were identified with 78 breast cancers. Seventy percent (48 of 69) were initially detected by palpation, whereas 30 percent (21 of 69) were initially identified mammographically. Fifty-three percent (n = 41) underwent mastectomy and 47 percent (n = 37) underwent a lumpectomy. This compares with a 63.6 percent (2615 of 4110) breast conservation rate in the nonaugmented population during the same time period. The two groups did not differ regarding (tumor) size (p = 0.77), nodal positivity (p = 0.32), or stage (p = 0.34). The mean time between implant placement and a diagnosis of breast cancer was 14 years. The average age of the patients who had previously undergone augmentation at breast cancer diagnosis was 49.5 years (SD, 9.0 years) versus 57.1 years (SD, 13.5 years) for the nonaugmented patients (p < 0.0001). Forty-nine of the patients underwent lymphatic mapping, with a 100 percent success rate in identifying the sentinel lymph node. There have been no clinically detected axillary recurrences in the patients who had a negative sentinel lymph node biopsy. Breast cancer patients who have undergone previous augmentation are more likely to present with a palpable mass. This initial mode of detection does not appear to translate into a larger tumor size or worse prognosis. Breast conservation and lymphatic mapping can be performed successfully in previously augmented patients.