Considerable controversy continues to surround the therapy of metastatic carcinoma of the prostate. Until recently orchiectomy and diethylstilbestrol (DES) were the only treatment options available. The development of megestrol acetate is of interest because of its broad spectrum of activity and excellent patient acceptability. Interim results of a study comparing megestrol acetate 120 mg/d plus mini-dose DES 0.1 mg/d with DES 3 mg/d are reported. Megestrol acetate had minimal side effects, with 2% of patients withdrawing from the megestrol acetate arm because of toxicity, compared with 37% from the DES arm. Significant cardiovascular toxicity occurred in 33% of patients taking DES and in 7% taking megestrol acetate. Both therapies achieved permanent suppression of serum testosterone to castrate levels. Time to progression and overall survival were longer with DES treatment, 17 versus 23 months and 24 versus 44 months, respectively, but this was not significant (P = .34 and P = .16, respectively). A review of the literature on the treatment of metastatic carcinoma of the prostate is presented to determine what should be recommended as standard therapy. Total androgen blockade is analyzed critically and results of therapy are compared with other modalities. Based on efficacy, cost, toxicity, and patient acceptability, orchiectomy still should be considered standard therapy and total androgen blockade should be considered experimental.