Background The safety and efficiency of transurethral laser resection of the prostate to treat benign prostatic hyperplasia have been verified. However, this method does still not manage large volume prostates efficiently. To tackle this problem, we have designed a method of transurethral dividing vaporesection of prostate using a 2 micron continuous wave laser. The aim of this study was to evaluate the safety and efficiency of this method in the management of large prostates (＞80 ml).Methods In this study, 45 cases of benign prostatic hyperplasia with a median prostatic volume of (123.7±26.7) ml (range, 80.2-159.8 ml) were treated by the same surgeon under epidural anesthesia. During the surgery, superapubic catheters were needed, and saline solution was used for irrigation. First, the prostate was divided longitudinally into several parts from the bladder neck to the prostatic apex, and then gradually incised transversely chip by chip. Intraoperative blood transfusion rate, postoperative complications, maximum urinary flow rate, Intational Prostate Symptom Score and quality of life scores were recorded for statistical analysis using SPSS 16.0 software.Results Intraoperatively, no transurethral resection syndrome was observed, and no blood transfusions were needed.The resected prostatic chips were easily flushed out of the bladder through the resectoscope sheath without the use of a morcellator. Median vaporesection time was (95.0±13.2) minutes (range, 75-120 minutes), and the median retrieved and removed prostatic tissue were (25.2±5.1) g (range, 15.5-34.7 g) and (75.4±16.4) g (range, 43.8-106.1 g), respectively. Median catheter time and hospital stay were (3.3±0.9) days (range, 3-5 days) and (4.8±1.8) days (range, 3-9 days), respectively. After a follow-up of 6 to 12 months, two patients had stress urinary incontinence and three had anterior urethral strictures. Satisfactory improvement was seen in maximum urinary flow rate, Intational Prostate Symptom Score and quality of life scores.Conclusions This study showed that 2 micron laser vaporesection is a safe treatment for benign prostatic hyperplasia patients with large prostates, and the method of dividing vaporesection may help improve both surgical efficiency and patient outcomes.