The current emphasis on early detection of breast carcinoma prompted an analysis of all breast biopsies performed at an urban teaching hospital between January 1, 1983, and December 31, 1987. There were 1,342 biopsies during this interval in 933 patients with an overall mean age of 45.3 years. Malignancy was diagnosed in 197 patients (14.7%) with a mean age of 57.5 years, while the remaining patients with a benign diagnosis had a mean age of 43.2 years. There were 178 nonpalpable lesions (13.3%) and 22 malignancies were detected in this group (12.4%). Most (91%) of the nonpalpable malignancies were "early" (in situ and stage I), while 71 per cent of the palpable malignancies were "advanced" (stages II and III). Although the yearly number of biopsies remained constant, upward trends were demonstrated in the number of nonpalpable lesions biopsied, the proportion of malignancies detected among all biopsies, and in the yield of proliferative benign forms of breast disease, specifically those with atypia. These trends correlated with a sixfold increase in the yearly number of mammograms performed over the same time interval. These results suggest that a commitment to an expanded use of mammography and to an aggressive approach to breast biopsy can increase the detection of both early forms of breast carcinoma and those benign breast lesions that are known pathologic risk determinants for breast carcinoma. Such a commitment may influence the future survival of this population.