Out of 62 patients with hormone-refractory metastatic prostate cancer, 34 received rescue treatment with estramustine phosphate and 28 received non-steroidal symptomatic treatment. All patients undergoing symptomatic treatment experienced increased PSA levels while in 16 (47%) patients treated with estramustine phosphate, PSA decreased between 13-96%. In 11 cases (32.3%) the decline in PSA was higher than 50%. In 5 (14.7%) the decline was lower than 50% and in 18 cases (53%) PSA levels were increased. SCR rate was 82%, 60% and 6% respectively while OCR were 36.4%., 0% and 0% respectively. No clinical response was seen in patients undergoing symptomatic treatment. A decline in PSA levels higher than 50% 12 weeks after treatment appears to be a "good prognosis" factor related to the best clinical response rates and survival.