Recently, there has been an increasing interest in the application of preoperative endocrine therapy prior to radical prostatectomy. The main purpose of this treatment modality is to enhance surgical curability and increase survival. Endocrine therapy was performed before radical prostatectomy on 40 patients between 1986 and 1993; 15 had stage B2 and 25 had stage C disease. The median duration of preoperative endocrine therapy was 3.8 months. All patients subsequently underwent radical prostatectomy, pelvic lymphadenectomy and castration. There was on average a 25.5% (0-71.8%) decrease in maximal cross-sectional area of prostate gland as determined by transrectal ultrasonography. Treatment-related histological effects, divided into three grades were as follows; excellent in 17, moderate in 11 and poor or no regression in 12. Pathological downstaging of disease status from the diagnosis made at the initial clinical examination was seen in 13 of the 40 patients (33%). At a median follow-up of 50 months (19-118 months), 36 of the 40 patients are disease-free and two died of cancer 43 and 50 months postoperatively. These findings suggest that preoperative endocrine therapy plays an important role in the management of locally advanced prostatic cancer.