OBJECTIVE: It has been shown the safety and efficacy of Nd:YAG laser treatment for benign prostatic hyperplasia (BPH). In this study we evaluate the safety and efficacy of this procedure in pts with BPH>70cc delivering high amount of energy. MATERIALS: This prospective study was conducted in 32 pts aged 52 to 84 years (mean 67.1) with a mean pre op prostate volume of 89 cc (r:70-174). Non-contact Nd:YAG laser treatment at 50 watts (W) for 60 seconds (SOW at the laser tip) was given via a Urolase fiber. Lesions were given less than 10mm apart, in both the sagittal and transverse planes. The mean number of lesions given was 36,5 (r:16-65), and the mean energy deliveres 109,406 Joules (r:48,000-195,000). All pts were discharged with a suprapubic catheter at 24 hours postop. RESULTS: The procedure was bloodless and uncomplicated in all cases. Postop complications include urinary tract infection in 4 pts (12.5%), epididymitis in 2 (6.3%), hematuria 2 weeks after laser treatment that required electrofulguraton in 2 (6,3%), and dysuria that lasted more than 2 weeks in 1 (3.1%). Other results are (mean): pre-op 3m 6m 12 m n=32 n=19 n=10 n=4 AUA 26,4 5,0 4,4 3,5 PF (cc/sec) 6,7 18,8 21,0 31,0 PVR(cc) 143,1 64,5 37,4 36,2 CONCLUSIONS: Our early results suggest that extensive photoirradiation of bigger prostates is a safe and effective alternative for the treatment of BPH, with low morbidity and short hospital stay and convalescence.