Toremifene (Fareston)-a novel antiestrogenic drug with a triphenylethylene structure-has been effective in the treatment of postmenopausal breast cancer patients. It is safely administered even in high doses up to 300 mg/day. The purpose of the study was to investigate the effect and tolerability of high dose toremifene in the treatment of patients with advanced renal cell carcinoma (RCC). Thirty six patients started the treatment with toremifene 300 mg/day. There were 26 males and 10 females. Mean age was 56.0 years, range 35-75 years. Nineteen patients were nephrectomized. One patient was not evaluable for response because of too short treatment time. The response rate was 17.1%, including 1 CR (2.9%) lasting for 121 + weeks and 5 PR (14.3%) with the mean duration of 39.8 + weeks. Ten cases of NC (28.6%) had the mean duration of 23.7 weeks. There were no significant differences in response rate when patients with lung metastases only were compared to patients with metastases of other sites with or without lung metastases. Total pain control was achieved in 45% and partial control in 20% of those patients who had pains in the beginning of the treatment. Ten patients (27.8%) had adverse reactions which led to discontinuation of the treatment in one case. It can be concluded that high-dose toremifene is an effective and safe means of palliative treatment in advanced RCC.