Objective To discuss the safety and effectiveness of transurethral resection of the prostate (TURP) on large-size (≥ 80 ml) benign prostatic hyperplasia (BPH).Methods Retrospective analysis of 958 BPH patients in Southwest Hospital during January 2010 to January 2013 was conducted.The patients were grouped into ≥80 ml prostate group (Group A) and ＜80 ml prostate group (Group B) according to the volume of prostate.Comparison was made between the 2 groups on the safety and effectiveness of TURP.Results There were 276 patients in Group A and 682 in Group B.No significant differences were shown in average age and preoperative American society of anesthesiology score of Group A and B.Compared with Group B,decrement in hemoglobin level and blood Na+ concentration of Group A was more significant (P＜0.01).There were more prostate tissues excised and duration of the operations was longer (P＜0.01).No significant difference was observed in peri-operative complications graded by the modified Clavien classification system,catheter durations and durations of hospital stay between the 2 groups (P＞0.05).At 6 months after the surgery,average maximum urinary flow rate (Qmax) increased from 5.9±2.9 ml/s to 17.1±8.2 ml/s for Group A and 6.1±3.0 ml/s to 17.5±6.4 ml/s for Group B,both groups showed significant increase in Qmax after surgery(P＜0.01).Six months after surgery,international prostate symptom score (IPSS) of Group A decreased from 23.7±6.1 to 5.9±4.9 while IPSS of Group B decreased from 23.1±5.5 to 6.2±4.4,both groups showed a significant decrease (P＜0.01).No significant difference was shown in IPSS,quality of life,Qmax,postvoid residual urine volume and occurrence rate of long-term complications after 6 months between the 2 groups (P＞0.05).Conclusion TURP is as safe and effective in treating large-size BPH as treating medium and small-size BPH.