To evaluate the safety and efficacy of transrectal high-intensity focused ultrasound (HIFU) in the treatment of benign prostatic hyperplasia (BPH), serial studies were conducted in 150 BPH pa- tients before and 30 min, 1, 2, 6 and 12 month(s) after Sonablate-500~(TM) HIFU treatment. A sili- con-coated indwelling 16F latex catheter was placed during the determination of the therapy zone. Preoperative and postoperative evaluations were made by using the international prostate symptom score (IPSS), quality of life (QOL), uroflowmetric findings and transrectal ultrasound, and incidence of complications. The cystourethrography was done in 23 patients within 1 year postoperatively. The results showed that after HIFU treatment, IPSS and QOL scores were significantly decreased at 1, 2, 6 and 12 month(s) (P<0.01). Maximum urine flow rate (6.0 to 17.2 mL/s, P<0.01), PVR (75.0 to 30.3, P<0.01) and prostatic volume (65.0 to 38.1 mL, P<0.05) were significantly improved 12 months after the operation. Recurrent urinary retention (n=2) and urethrorectal fistula (n=1) occurred at the 15th postoperative day. The duration of the HIFU prostate ablation was 25–90 min. The mean time for an indwelling catheter was 3–19 days. These data demonstrate that treatment of BPH with Sonab- late-500~(TM) HIFU is safe and effective. To evaluate the safety and efficacy of transrectal high-intensity focused ultrasound (HIFU) in the treatment of benign prostatic hyperplasia (BPH), serial studies were conducted in 150 BPH pa- tients before and 30 min, 1, 2, 6 and 12 month (s) after Sonablate-500 ~ (TM) HIFU treatment. A sili- con-coated indwelling 16F Latex catheter was placed during the determination of the therapy zone. Preoperative and postoperative evaluations were made by using the international prostate symptom score (IPSS) The quality of life (QOL), uroflowmetric findings and transrectal ultrasound, and incidence of complications. The cystourethrography was done in 23 patients within 1 year postoperatively. The results showed that after HIFU treatment, IPSS and QOL scores were significantly decreased at 1, 2 , 6 and 12 months (s) (P <0.01). The maximum urine flow rate (6.0 to 17.2 mL / s, P <0.01), PVR (75.0 to 30.3, P <0.05) were significantly improved 12 months after the operation Recurrent urinary retention (n = 2) and urethrorectal fistula (n = 1) occurred at the 15th postoperative day. The duration of the HIFU prostate ablation was 25-90 min. The mean time for an indwelling catheter was 3-19 days. These data demonstrate that treatment of BPH with Sonab-late-500 ~ (TM) HIFU is safe and effective.