135 consecutive patients aged over 70 years with operable primary breast cancer (clinically maximum diameter 5 cm) were randomised to either wedge mastectomy or tamoxifen 20 mg twice daily as initial therapy. The mean time from randomisation is now 65 months. There was no difference between the two groups in terms of overall survival or cause of death. Likewise, the groups were similar for site of initial metastatic disease and the probability of developing metastatic disease. However, failure of locoregional control was significantly greater in the tamoxifen group. The optimum treatment for elderly patients with operable breast cancer includes mastectomy.