We report the outcome of photoselective vaporizaion of the prostate (PVP) with the 180W GreenLight XPS™ system (180 W-XPS) for large benign prostatic hyperplasia (BPH) with a prostate volume of ≥100 ml, in comparison with that with the 120 W GreenLight HPS™ system (120 W-HPS). We studied the outcomes of 86 patients who underwent PVP with 180 W-XPS for BPH with a prostate volume of ≥100 ml between February 2019 and October 2021, in comparison with those of 86 patients who underwent PVP with 120 W-HPS. 180 W-XPS significantly improved postoperative international prostate specific score, quality of life score, overactive bladder symptom score, Qmax, and residual urine volume. The operative time was significantly shorter in 180 W-XPS {100.5 min (150-175)}, than in 120 W-HPS {117.5 min (18-189)}, p＜ 0.05), the laser irradiation time was significantly shorter in 180 W-XPS {63.0 min (35-83)}, than in 120 WHPS : {79. 0 min (24-102)} (p ＜0. 05), and the laser fluence was significantly higher in 180 W-XPS {633647J (291991-805011)}, than in 120 W-HPS {396832J (40000-481842)} (p＜0. 05). At 3 and 12 months postoperatively, the prostate volume reduction rates were 59.8 and 66.7%, respectively, for the 180 W-XPS patients which were rates significantly higher than those for the 120 W-HPS patients, 49.5 and 45.0%, respectively. The PSA reduction rates were 58.1 and 53.2％, respectively, which were significantly higher rates than those for the 120 W-HPS patients, 41.3 and 25.7％, respectively. The 180 W-XPS system was considered to be a more effective and efficient treatment than the 120 W-HPS.