About 40 percent of newly diagnosed breast cancers occur in women older than 65. Hormonotherapy plays an important role as adjuvant treatment of primary cancers in post-menopausal women because of their great hormone-dependence. The drug of choice is tamoxifen which is very well tolerated. Its beneficial effect appears to be related to the duration of administration. It also seems to be particularly promising in the initial treatment (neoadjuvant) of elderly women and potentially beneficial in the breast cancers said to be of good prognosis when the axillary nodes are not involved.