Objective: This study aimed to assess the perioperative and the 12-month efficacy and safety of 140 W highpowered holmium laser for enucleation of the prostate (HP-HoLEP) for the treatment of benign prostatic obstruction. Material and methods: The data of 540 patients who underwent HoLEP by a single surgeon were analyzed retrospectively. Preoperative evaluation included a physical examination with a digital rectal examination, measurement of maximum urinary flow rate (Qmax), postvoid residual volume (PVR) and prostate volume by transabdominal ultrasonography, serum prostate-specific antigen (PSA), international prostate symptom score (I-PSS) and international index of erectile function-5 (IIEF-5) questionnaires, and urine analysis. Morcellation, enucleation, and operation efficiencies were calculated with the resected weight divided by morcellation, enucleation, and operative times, respectively. The patients were reassessed at 1, 3, 6, and 12 months after surgery by I-PSS, IIEF-5, Qmax, PSA, and the occurrence of complications. Results: The mean operative time was 65.2±20.9 minutes. The mean enucleation time and efficiency were 53±15.1 minutes and 1.72±0.4 g/min, respectively. The mean morcellation time and efficiency were 12.3±15.1 minutes and 7.4±3.2 g/min respectively. Clavien grade 1 complications were observed in 102 (18.9%) patients, Clavien grade 2 complications in 20 (3.7%) patients, and Clavien grade 3b complications in 23 (5.4%) patients. I-PSS, Qmax, and IIEF-5 at postoperative 1, 3, 6, and 12 months were significantly better than baseline results. Conclusion: Our study demonstrated that 140 W HP-HoLEP can be performed with high enucleation efficiency, low perioperative and postoperative complication rates, and excellent functional results.