To report on the combined use of Nd:YAG contact laser incision and Nd:YAG non-contact coagulation necrosis in the treatment of benign prostatic hypertrophy (BPH). This modification has the advantage of providing early improvement of voiding function and preservation of antegrade ejaculation. Between November 1998 and March 1999, 31 patients with voiding dysfunction secondary to BPH, with a prostatic size less than 30 ml, were enrolled in this study. Nd:YAG contact laser was used to incise the prostate with the technique of Orandi's transurethral incision of prostate. The incision line was vaporized to a 3-5mm trough. The prostatic adenoma was then coagulated by the free beam of the Nd:YAG laser in order to increase volume reduction. The prostatic tissue 0.5 to 1.0 cm proximal to the verumontanum was preserved during the procedure. A Foley catheter was removed at noon on the first postoperative day, and the patient was discharged on the second postoperative day if he could void without assistance. Preoperative and postoperative parameters were analyzed by the Wilcoxon signed ranks test. The 31 patients had a mean age of 63.3 years, and a mean prostatic volume of 18.2ml. The preoperative parameters were compared to the postoperative parameters at 6 months following the procedure. The mean peak flow rate was 8.13 ml/s vs. 14.5 ml/s(p<0.01); the mean IPSS score was 24.0 vs. 7.31 (p<0.0l); the mean residual urine volume was 51.9 ml vs. 28.9 ml(p=0.144). The mean operative time was 53 minutes. Twenty-nine(93.5%) of the patients could void by themselves on the first postoperative day and the mean peak flow rate was increased to 12.3 ml/s. Fifteen (93.8%) of the 16 patients achieved preservation of antegrade ejaculation. There was neither water intoxication nor massive bleeding postoperatively. This modification of the Nd:YAG laser prostatectomy technique is a good alternative treatment for BPH of less than 30 ml. More than 90% of the patients could void by themselves within 24 hours after operation. The improvement of urinary flow rate was immediate and greater than 50%, and this improvement lasted for 6 months. Preservation of antegrade ejaculation in 94% of the patients is another advantage of this treatment.