The use of nonsteroidal antiandrogens as first-line therapy for the treatment of cancer of the prostate is discussed. The results of studies using flutamide as monotherapy are reviewed and show flutamide to be an effective agent in the treatment of metastatic prostate cancer. Comparative studies have shown that flutamide monotherapy is as effective as standard hormonal treatment, with no difference in the two treatments. In one study, treatment with diethylstilbestrol was found to be superior to flutamide in terms of survival. Further studies are required before the use of pure antiandrogen monotherapy can be recommended for the treatment of metastatic prostate cancer.