Between 1984 and 1989, 197 patients with T1-4, NX, M1, G2-3 or G3 prostate cancer were randomized to treatment with 560 mg estramustine phosphate (EMP, Estracyt, Emcyt) or 3 mg diethylstilbestrol (DES) per day in a double blind study with stratification on presence or absence of cancer pain at start. A total of 194 patients were evaluated for efficacy of therapy. Time to progression (p = 0.054), to treatment failure (p = 0.036), cancer-specific survival (p = 0.068) as well as overall survival (p = 0.021) were longer in the DES group. There were more patients with prognostic parameters indicating bad prognosis in the EMP group. This trial was designed to study whether EMP had better effect than DES as the primary treatment of high-grade, disseminated prostate cancer. The results did not confirm this hypothesis. On the contrary, treatment with DES had relatively good effect on this very aggressive form of prostate cancer.