Approximately 50% of new breast cancers occur in women aged 65 and older, and the incidence and prevalence of breast cancer among older women are expected to increase in the future. Moreover, in the past years, life expectancy has increased exceeding 10 years in patients aged 75 years. Aging is associated with a decline in the functional reserve of multiple organ systems, an increase in the prevalence of functional dependence, comorbidity and memory disorders, and a decline in economic resources and social support. All these aspects should be evaluated using some form of geriatric assessment, to rule out unsuspected conditions that may interfere with cancer treatment. Even if the course of breast cancer is more indolent in older than in younger women, up to 20% of women older than 70 years of age have aggressive hormone-receptor-poor tumors. Adequate surgical resection is the mainstay treatment for primary breast cancer even in older women. Lymph node dissection remains a major component of staging and local control, however owing to the sentinel lymph node technique, only women whose sentinel lymph node is invaded by the tumor do need full dissection. Radiation therapy reduces the recurrence rate for any category of tumors, including those occurring in older individuals. Adjuvant hormonal therapy should be recommended to women whose breast tumors contain hormone receptors, regardless of age, involvement of axillary nodes or tumor size. Tamoxifen is the most commonly used hormonal therapy, with data supporting one to five-year course of treatment in elderly patients. Recent results from trials comparing tamoxifen to aromatase inhibitors (anastrozole, letrozole and exemestane), given at different time points, have reported superior results of these drugs over tamoxifen in terms of disease-free survival but not of survival. Aromatase inhibitors can be considered for elderly women according to the degree of risk and biological features, and in those with contraindications to tamoxifen. As reported in the 2005 Early Breast Cancer Trialists Collaborative Group (EBCTCG) analysis, trials of adjuvant chemotherapy involved few women older than 70 years of age to be reliably informative as to whether it confers any survival benefit in this age group. For patients with hormone receptor negative tumors few specific published data are until now available, partly because these tumors represent a small subset in adjuvant studies in the elderly, and also because the distinction between ER poor and ER negative tumors is still a matter of controversy. It would be advisable to participate in currently open clinical trials that are addressing this issue. There is reluctance to prescribe systemic treatments due to the complexity of evaluation for these patients. Taking into account the limited amount of data and uncertainty regarding optimal treatment, individualized care on the basis of biologic characteristics, comorbidity, social support, functional status, and patient preferences should be considered. Trials of tailored adjuvant therapy should be a health care priority.