A total of 20 patients with benign prostatic hyperplasia underwent transrectal local hyperthermia. For heating of the prostate gland, the PROSTATHERMER (Biodan-Medical System, Israel) was used. Patients were treated twice weekly, for 1 hour, with 6 sessions on an outpatient basis. Four of the 20 patients who had acute toxicity such as urethral irritability due to urethral thermoprobe could not tolerate the treatment. In the majority of the patients who were completely treated, a significant decrease in frequency of nocturia, decrease in post-void residual urine capacity and increase in urine flow rate were observed. No significant change in prostate volume was noted. With a mean follow-up of 6 months, only 1 patient required subsequent prostatic resection. These findings indicate that local hyperthermia applied by this method is effective in the treatment of benign prostatic hyperplasia and that improvement of the thermometry system is needed.