The efficacy of high dose toremifene (240 mg daily) in postmenopausal women with advanced breast cancer is investigated in this ongoing study. At present, 38 patients are fully evaluable. Ten patients have CR (26%), 16 PR (42%) (objective response rate 68%), 8 NC (21%), and 4 PD (11%). Most objective responses are in soft tissue tumors (14/17, 82%). The response rate is equally high in patients with positive or unknown estrogen receptor (ER) status. Median duration of responses and survival are not yet evaluable. Of 48 patients evaluable for side-effects, 22 (46%) experienced some kind of toxicity, which was mild in 64% of cases, moderate in 29%, and mostly of estrogenic type. The study will continue to confirm the results thus far obtained.