OBJECTIVE To compare the clinical outcomes between thulium laser transurethral enucleation of the prostate (ThuLEP) (70 W) and holmium laser transurethral enucleation of the prostate (HoLEP) (90 W) in a prospective randomized trial with 18 months of follow-up. Both ThuLEP and HoLEP effectively relieve the obstructive symptoms due to benign prostatic hyperplasia (BPH). METHODS A total of 133 consecutive patients with BPH were randomized to either ThuLEP (n = 71) or HoLEP (n = 62). An energy setting of 70 W and 90 W was used for the thulium and holmium laser in the enucleation procedure, respectively. The mushroom technique was used to fragment the enucleated lobes with the resection loop. The preoperative and postoperative parameters were compared. RESULTS ThuLEP required a longer operation time (72.4 vs 61.5 minutes, P = .034) but resulted in less blood loss than HoLEP (130.0 vs 166.6 mL, P = .045). The catheterization time was comparable. At 18 months, the lower urinary tract symptom indexes were improved significantly in both groups compared with the baseline values. The International Prostate Symptom Score decreased to 5.2 in the ThuLEP group and 6.2 in the HoLEP group. The quality of life score and peak urinary flow rate were similar between the 2 groups (1.3 vs 1.2 and 23.4 vs 24.2 mL/s) and the postvoid residual urine volume decreased by 82.50% and 81.73% in the ThuLEP and HoLEP groups, respectively. The mean prostate-specific antigen decrease after HoLEP and ThuLEP was 30.43% and 43.36%, respectively. No urethral or bladder neck stricture were found in either group. CONCLUSION Both ThuLEP (70 W) and HoLEP (90 W) relieve lower urinary tract symptoms equally with high efficacy and safety. ThuLEP was statistically superior to HoLEP in blood loss and inferior to HoLEP in operation time, although the differences were clinically negligible. The mushroom technique could be adequate, without an additional mechanical tissue morcellator. UROLOGY 79: 869-874, 2012. (C) 2012 Elsevier Inc.