A total of 591 patients with advanced prostatic cancer have been randomized to either orchiectomy or treatment with zoladex 3.6 mg as a depot preparation combined with flutamide 250 mg tid in two European studies, EORTC protocol 30853 and DAPROCA 86. Identical design and comparable patient characteristics in the two studies have allowed combined analysis. A small but statistically significant difference in time to objective progression or death from prostatic cancer was found in favor of the combination treatment. However, time from objective progression to death was longer in the group initially allocated to orchiectomy. Thus, no difference between treatment groups in overall survival was found. As a conclusion, the combined androgen blockade was not superior to orchiectomy in the treatment of patients with advanced prostatic cancer.