Breast cancer is a common problem in older women. As the number of medical illnesses increases with age and the life expectancy decreases, the benefits of systemic therapy for women with breast cancer become questionable. All women over age 65 years are at high enough risk of breast cancer to consider the risk/benefit ratio of preventive therapy with tamoxifen (Nolvadex) or participation in the Study of Tamoxifen and Raloxifene (STAR) trial. Adjuvant chemotherapy and hormonal therapies for early breast cancer significantly improve disease-free and overall survival; recommendations for their use are based on risk of tumor recurrence. Use of tamoxifen in the adjuvant setting in women with receptor-positive tumors is a relatively simple decision in light of its favorable toxicity profile. The delivery of adjuvant chemotherapy is a more complicated decision, and the patient's wishes, estimated life expectancy, presence of comorbid conditions, and estimated benefit from treatment should be considered. The primary goal of the treatment of metastatic breast cancer is palliation. We discuss trials specific to older women and make appropriate treatment recommendations. Unfortunately, there is a paucity of data from clinical trials in women over age 70 years. However, because the clinical trial is the primary scientific mechanism for testing the efficacy of a treatment, every effort should be made to enter older women into treatment protocols.