320 mg of serpense was given daily to 24 patients with benign prostatic hyperplasia (BPH) for 2 months. Control check-ups were performed each 30 days. The effect was judged by the patient's condition (I-PSS), quality of life, residual urine, the gland size, urodynamic picture and level of prostatic specific antigen (PSA). The response of BPH to serpense was noticeable, especially at the first stage of the disease (66.7%). Reduced serum PSA in serpense-treated patients may be explained by peripheral selective inhibition of 5 alpha-reductase or, rather, by anti-inflammatory action of the drug. Antidropsical and antiinflammatory actions of serpense suggest its possible efficacy in chronic prostatitis.