By the end of the 20th century, more than 50% of new breast cancer patients will be greater than 65 years old. Until recently, research focused on this older group of women has been minimal. Previous studies have indicated that the elderly are less likely to be screened, and have lesser and frequently inferior treatment. In contrast, the few clinical trials focusing on the elderly suggest that they do as well with surgery, radiation, and standard chemotherapy regimens as their younger counterparts. Comorbidity is, however, more common in older women, and must be factored into treatment and prognosis. The available data indicate that mammography should be used on a yearly to every-other-year basis for screening older women, including those older than 70 years and in fair to good health. Older women should offered breast preservation options and should receive breast radiation following lumpectomy. Tamoxifen may be used as initial therapy for frail women with early to late stage breast cancer, but is inferior to surgery in achieving long-term local control. Adjuvant tamoxifen should be considered for all high-risk node-negative and all node-positive patients regardless of receptor status. Adjuvant chemotherapy is reasonable for high-risk node-negative and node-positive patients in good health and with reasonable life expectancy (>5 years), although clinical trials have not established efficacy for women in this age group. Older women with metastatic breast cancer are good candidates for endocrine therapy. Chemotherapy should be offered to those with progressive disease after endocrine therapy. There are inadequate numbers of older women enrolled in breast cancer clinical trials. Both physicians and patients should explore and define the barriers to clinical trial participation and develop successful interventions to overcome them.