A specifically designed system of selective prostate heating was used to treat 197 patients with prostatic diseases: 164 benign prostatic hypertrophy cases, 14 prostatic adenocarcinoma cases, 19 chronic abacterial prostatitis cases. Ninety-one benign prostatic hypertrophy patients could be evaluated at the three month follow-up date. Sixty-eight patients complained of severe obstructive symptoms and 23 had an indwelling catheter. Prostates were heated up to 42 +/- 0.5 degrees C during 60 minute long sessions, once or twice a week for five weeks. Local prostatic hyperthermia determined a marked amelioration of the clinical picture in 67% of patients who presented without an indwelling catheter. Sixteen patients (70%) were weaned off the catheter. Major complications were not encountered.