The aim of this study was to investigate the effect of intensity of cutting power on postoperative symptoms after transurethral resection (TURP) with a monopolar system for benign prostatic hyperplasia. One hundred thirty-six men with benign prostatic obstructions undergoing elective transurethral prostatectomy were enrolled in the study. Patients were divided into three groups according to the intensity of cutting power. The cutting power intensities were 80-119 W for group 1, 120-159 W for group 2, and 160-200 W for group 3, respectively. In the postoperative period, patients were evaluated with International Prostate Symptom Score (IPSS) and quality-of-life (QoL) questionnaires. In the postoperative period, maximal flow rate (Q(max)), and post-voiding residue (PVR) were significantly improved in patients who had monopolar TURP performed. When compared to the other groups, the IPSS score was found to be significantly higher in group 3 at 3, 4, and 8 weeks. In addition, the QoL assessment scores for group 3 were superior at 3 weeks. The improvements of Q(max) and PVR were similar among the three groups (p<0.0001). At the end of 3 months, IPSS and QoL were significantly improved in all groups. The intensity of cutting power during prostate resection with a monopolar system may affect the postoperative improvements and symptoms.