Short-term data suggest that bipolar transurethral resection of the prostate (B-TURP) is safer than the monopolar technique (M-TURP). Mid-term (36 months) safety comparisons have now been reported from a large trial. Safety was estimated by rates of urethral strictures and bladder neck contractures (BNCs). Efficacy was quantified by urodynamic changes from baseline and was similar between M-TURP and B-TURP. 10 urethral strictures were reported in each arm; 2 men receiving M-TURP and 8 receiving B-TURP experienced BNC. At one of the longest durations studied thus far, M-TURP and B-TURP are similar in terms of efficacy and safety.