Objective To compare the efficacy and safety of hybrid laser treatment, i.e. the combination of visual Nd-YAG laser ablation of prostate and contact Nd-YAG laser vaporization of prostate, with transurethral resection of the prostate (TURP) in the treatment of patients with symptomatic bladder outlet obstruction secondary to a benign high-volume prostate. Patients and methods Forty-five symptomatic patients with hyperplastic prostates of >40 mL were randomized to undergo either hybrid laser treatment (21) or TURF (24). All patients were evaluated before and after treatment with a complex urodynamic assessment, and were accepted into the study only if they had infravesical obstruction in the pressure-now study. In the hybrid method, Nd-YAG laser energy was first delivered by an 'adenoma-dependent' approach to all areas of the obstructing lateral lobe tissue through a side-firing gold-alloy tip fibre at 40 W for 90 s of 'burn'. The prostatic urethra was then opened and the median lobe vaporized using the a contact probe at 40 W. Patients were re-evaluated 3 and 6 months after treatment, Results Both treatments proved to be safe, and improved the subjective and objective outcome measures at 3 and 6 months compared with baseline values. After 3 months, there was a greater improvement in the TURF group in peak urinary flow rate (Q(max); P< 0.01), mean urinary flow rate (Q(ave); P < 0.01) and postvoid residual urine volume (P<0.05) than in the hybrid laser group. After 6 months, there was a greater improvement in the TURF group in detrusor pressure at Q(max) (P < 0.01), Q(ave) (P < 0.05) and prostate size (P < 0.001) than in the hybrid laser group. In the pressure-flow study at 6 months, a higher proportion of patients (seven of 19) were still obstructed in the hybrid laser group than in TURF group (two of 21; P<0.05). TURF caused more intraoperative blood loss (P<0.001) and postoperative problems associated with bleeding; 38% of hybrid laser patients were discharged with a suprapubic catheter, whereas all TURF patients could urinate at discharge (P<0.01). The duration of bladder drainage was longer after hybrid laser treatment (P<0.001). Conclusion The hybrid laser method was a safe but less effective treatment than TURF for benign prostatic enlargement in patients with prostates of > 40 mL.