The authors report on a series of 120 elderly (age over 69) women with primary breast treated with tamoxifen alone. Treatment schedule was 160 mg on day 1 followed by a daily maintenance dose of 20 mg. Compliance to treatment was optimal and side effects were minimal. The best results achieved after at least six months of treatments were complete response in 12, a partial response in 46 and minor response in 10 patients, whereas stable disease or progression was observed in 43 or 9 patients, respectively. Response duration was limited and progression was increasingly observed over time. After 6, 12, 24, 36, 48 and 60 months the proportion of subjects still showing response to treatment was 43%, 57%, 56%, 46%, 32% and 31%, whereas progression rate was 7%, 12%, 25%, 39%, 55% and 60%, respectively, the difference being accounted for by patients with stable disease. As determined in a subset of 27 subjects, treatment response was strongly associated with immunocytochemically assessed tumor estrogen receptor content, progression being 100%, 43% or 6% in subjects with 0%, 30-60% or > 60% immunostained cells, respectively. These results do not support primary hormone therapy as a current alternative to surgery, which should be the standard treatment in otherwise healthy elderly patients with operable breast cancer. When surgery is specifically contraindicated, hormone treatment should be proposed as an alternative only in subjects with high tumor estrogen receptor content.