To evaluate the usefulness of total androgen blockade (TAB) therapy, we retrospectively studied 45 patients with prostate cancer who received TAB therapy as the first-line treatment. The clinical stage was A2 in 1 patient, B1 in 10, B2 in 9, C in 6, D1 in 3 and D2 in 16. Seven, 25 and 13 patients had well, moderately and poorly differentiated adenocarcinomas, respectively. The patients were placed on 1 of 3 TAB regimens: Luteinizing hormone-releasing hormone (LH-RH) agonist and flutamide (group 1), LH-RH agonist and chlormadinone acetate (group 2) and a surgical castration and flutamide (or chlormadinone acetate) (group 3). The therapeutic effect was evaluated at 12 weeks according to the response criteria in the general rules for clinical and pathological studies on prostatic cancer. The overall response was partial response (PR) in 35 patients (77.8%), no change (NC) in 6 (13.3%) and progressive disease (PD) in 4 (8.9%). PR was obtained in 81.3, 79.2 and 60% of the patients in groups 1, 2 and 3, respectively. One patient with PD responded briefly to flutamide withdrawal. None of the patients developed any severe adverse effects. In conclusion, the first-line TAB therapy is effective for prostate cancer with a lower risk than estrogens. Relapsed cases should be followed for flutamide withdrawal syndrome during TAB therapy.