PURPOSE: We evaluated our initial experience with the GreenLight HPS laser, a technologically improved version of the potassium-titanyl-phosphate (KTP) laser for PVP. MATERIALS AND METHODS: Transurethral PVP was performed using a GreenLight HPS side-firing laser system. Patients had American Urological Association Symptom Score (AUASS), Quality of Life (QoL) score, Sexual Health Inventory for Men (SHIM) score, serum prostate specific antigen (PSA), maximum flow rate (Qmax) and post void residual (PVR) determinations and volumetric prostate measurements with transrectal ultrasonography (TRUS). Laser and operative times and energy usage were recorded. AUASS, QoL, SHIM, Qmax and PVR were evaluated 1, 4, 12, 24, and 52 weeks post-surgery. Serum PSA and TRUS were obtained at 12 weeks and serum PSA was repeated at 52 weeks. RESULTS: Seventy consecutive patients with a median age of 67 (45-86) years underwent GreenLight HPS laser PVP from July 2006 through March 2008. Median prostate volume was 61.6 (20.9-263.0) mL with a median PSA of 1.4 (0.1 -10.1) ng/mL. Mean laser and operative times and energy usage were 13 (3-34) minutes, 30 (6-100) minutes and 85 (11-235) kJ, respectively. All were outpatient procedures with 49 (70%) patients catheter-free at discharge. No urethral strictures or urinary incontinence were noted. Median AUASS decreased from 22 to 8, 6, 5, 5, and 4 (p<0.001) while the median Qmax increased from 9.4 to 20.4, 20.3, 21.2, 18.8, and 20.0 mL/s (p<0.001) during the follow-up period. CONCLUSIONS: At one year, our experience suggests that GreenLight HPS laser PVP is safe and effective for treating lower urinary tract symptoms secondary to BPH.