The authors report on a consecutive series of 62 evaluable, elderly (age greater than 69 years) women with primary operable breast cancer treated only with tamoxifen. The treatment schedule was 160 mg on day 1 followed by a daily maintenance dose of 20 mg. Compliance to treatment was excellent, and subjective side effects were minimal. The best response achieved after at least 6 months of treatment was complete in 7, partial in 22 and minor in 3, whereas stable disease or progression was observed in 28 and 2 patients, respectively. The response rate decreased and progressions increased with time. At 6, 12, 24, 36 and 48 months of treatment, the complete + partial response rates were 30.6%, 45%, 45.6%, 38.7% and 25% and the progressive disease rates 4.8%, 19.6%, 34.8%, 45.2% and 66.6%, respectively. These results do not confirm some previous reports of a high response to tamoxifen. This difference is only partially explained by the use of mammography, which is more sensitive than palpation, to assess tumor size and treatment response. The present study does 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.