Cernilton was given clinically to 30 patients with benign prostatic hypertrophy. Cernilton was given orally at least for 12 weeks at a daily dose of 6 tablets in three divided doses. The overall clinical efficacy on subjective symptoms was 80%, and that on objective signs, 43%. During the administration period of Cernilton, no serious untoward effects were observed in either the clinical or laboratory findings. It is, therefore, suggested that, from the clinical point of view, Cernilton is a useful and safe drug in the treatment of benign prostatic hypertrophy.