From 1981 to 1995, 1755 patients aged 70 years or over who had nonmetastatic unilateral breast carcinoma received curative local or regional treatment in our institute. Median follow-up was 8 years. The median age of these patients was 75 years (range: 70-94), and 86% were under 81 years of age. Tumors were classed as T3-4 in 24% of them; 18% had N1b/N2 tumors, and in 12% grade 3 disease was present. Only 19% were both ER and PR negative. The S phase fraction was <5% in 79% of patients. In 1046 patients (60%) modified radical mastectomy was performed, while 20% underwent lumpectomy and in 20% radiotherapy was the only treatment administered. Adjuvant endocrine therapy was given in 463 (26%) cases, and only 3% of patients received chemotherapy. The median overall survival time was 121 months. The overall cancer-related death rate was 49%. The 10-year disease-free survival (DFS) rate was 64%, and the 10-year local relapse rate was 14%. Prognostic factors determined on univariate analysis were tumor size, clinical nodal status (ER and PR), and grade. No significant difference in outcome was observed between mastectomy and conservative treatment. Parameters for which correlations with DFS were found on multivariate analysis were clinical nodal status (P < 0.0001), tumor size (P < 0.0001), ER (P < 0.0001), and PR (P = 0.04). Breast cancer in elderly women is frequently hormone-dependent (81%) with a low proliferation index. Prognostic factors are the same as in younger postmenopausal patients. More than 50% of these patients died from a cause other than their breast cancer.