Objectives: In spite of a great amount of data, the hormonal treatment of advanced prostatic carcinoma (CaP) still remains controversial. As a relevant amount of dihydrotestosterone is present within the prostate tissue after castration, complete androgen blockade (CAB), with inhibition of the activity of both testicular and adrenal androgens, has been advocated as up-front treatment of advanced CaP. However, many controlled studies have failed to demonstrate a benefit for CAB in comparison with simple surgical or chemical castration. The present study was performed to bring additional data for a worldwide meta-analysis of all phase III trials comparing castration and CAB. Methods: This is a centrally controlled phase III study in which chemical castration with leuprorelin acetate depot was compared with leuprorelin plus flutamide in stage C and D CaP. Two hundred and forty-one eligible and evaluable patients with histologically proven CaP were recruited for the study (120 treated with castration and 121 with CAB). The diagnostic and staging workup consisted of blood chemistry, general condition assessment, prostate-specific antigen (PSA), abdominal sonography and computed tomography scan, and whole-body isotopic bone scan. End points of the study were survival, time to treatment failure, and time to progression. The patients were followed every 6 months with PSA and sonography. Results: At a cut-off analysis performed in December 1996, when the mean follow-up period was 43.7 ± (SD) 24.1 months, no statistical differences in terms of time to treatment failure, time to progression, and death rate could be detected. Also considering the common risk factors, such as basal PSA, haemoglobin, alkaline phosphatase, and Gleason score, the outcome did not show any clear advantage for CAB. Conclusions: This study appears to confirm that the advantages of first-line CAB in CaP are at best marginal. The final analysis will be performed when the follow-up period has reached 5 years, but it seems unlikely that the present results will change.