Objective To investigate the efficacy and safety of transrectal ultrasound guided transurethral balloon dilation of the prostate (TUDP) for the treatment of benign prostatic hyperplasia (BPH).Methods A total of 23 men with BPH who had undergone TUDP were retrospectively analyzed,including 16 men with indwelling urinary catheters before the operation.During the TUDP,the prostatic apex and membranous urethra were dilated by inner balloon,and the prostatic urethra and bladder neck were dilated by outer balloon.The patients were followed up at the 1st,3rd,6th and 12th month after the operation,and the observation parameters included subjective symptoms,such as international prostatic symptom score (IPSS) and quality of life (QOL) score,and objective parameters,such as maximum flow rate (Qmax) and post-void residual (PVR).Results The operation time was 30-165 min,and the intraoperative hemorrhage volume was 5-50 ml.The IPSS scores at 1st,3rd,6th and 12th month after the operation were 10.4± 4.2,8.7±3.2,9.5±4.6 and 8.3±1.5 respectively,which were significantly decreased in comparison to the IPSS score (22.0±7.2) before the operation (P<0.05).The QOL scores at 1st,3rd,6th and 12th month after the operation were 2.1±1.1,1.6±1.0,1.8±1.1 and 1.6±1.0 respectively,which were significantly improved in comparison to the QOL score (4.9±0.9) before the operation (P<0.05).The Qmax at 1st,3rd,6th and 12th month after the operation were (10.5±3.4),(12.4±4.2),(10.9±3.9) and (12.7±4.6) ml/s respectively,which were significantly increased in comparison to the Qmax(1.9± 1.9 ml/s) before the operation (P<0.05).There were 5,4,2 cases of urinary incontinence at the 1st,2nd and 3rd month after the operation,but they recovered at the 4th month follow-up.Besides,there were 3 cases suffered from epididymitis.Conclusion Transrectal ultrasound guided TUDP is a safe,effective and cheap option for the treatment of BPH,especially for the primary hospitals. Key words: Ultrasound guided; Transurethral balloon dilatation of the prostate; Prostatic hyperplasia; Treatment outcome