To prevent treatment withdrawal due to flutamide-induced liver dysfunction, we performed maximum androgen blockade (MAB) therapy by combining a luteinizing hormone-releasing hormone agonist or orchiectomy with low-dose flutamide (125 mg x 2/day) in patients with prostate cancer. In this study, the efficacy, adverse effects such as hepatotoxicity, and compliance were compared retrospectively between 35 patients who received low-dose flutamide therapy (1995-1999) and 27 patients who received flutamide at its ordinary dose (125 mg x 3/day). No significant difference was observed in the response rate (> or = PR) as determined from the prostate-specific antigen parameter (p = 0.6211) or the incidence of hepatotoxicity based on the aspartate aminotransferase and alanine aminotransferase levels. However, flutamide withdrawal due to liver dysfunction was less frequent in the low-dose group (2.9%) than in the ordinary dose group (18.5%) (p = 0.0386). MAB therapy using low-dose flutamide is expected to prevent the reduction in the compliance due to side effects and to improve the long-term prognosis in patients with prostate cancer, who are mostly elderly individuals.