This report is the final analysis of an EORTC Genito-Urinary Group Phase III trial (Protocol 30805) comparing orchidectomy, orchidectomy plus cyproterone acetate 50 mg 3 times a day and stilboestrol 1 mg daily in the management of metastatic carcinoma of the prostate. Three hundred and twenty-eight eligible patients admitted into the study have been followed up for a median period of 4 years. There was no difference in time to metastatic progression and overall survival between the treatment arms. The cardiovascular toxicity of stilboestrol 1 mg daily has resulted in more cardiovascular deaths as compared with the orchidectomy treatment arm. The outcome for individual patients has been determined by on-study prognostic factors, especially the performance status, rather than the treatment given.