Laser treatment of benign prostatic hyperplasia has enjoyed growing popularity among urologists over the last few years. Various applicators and techniques have been reported. Because this may result in a different overall performance, we performed a prospective randomized study comparing the results of treatment using the Ultraline fiber (n = 44) with that using the Urolase fiber (n = 49). Although different types of fibers and techniques were used, the results of this study were surprisingly similar for both fibers used. The uroflow for the Ultraline group increased from an average of 7.9 ml/s at baseline to 19.3 ml/s at 3 months and 16.9 ml/s at 6 months. In the patients treated with the Urolase fiber the uroflow improved from an average of 7.8 ml/s at baseline to 19.5 and 16.3 ml/s at 3 months and 6 months, respectively. The improvement in symptoms, reflected by changes in the I-PSS symptom scores, for the Ultraline group went from 21.0 at baseline to 7.9 at 3 months and 6.0 at 6 months. The Urolase patients improved from 21.0 at baseline to 8.2 and 5.6 at 3 and 6 month, respectively. The morbidity mainly consisted of a prolonged need for posttreatment catheterization and irritative symptoms lasting for about 2-4 weeks. From this study we conclude that the results achieved by laser treatment of the prostate using the Ultraline and Urolase fibers are both equivocal and excellent; however, the morbidity of these treatments remains considerable.