Purpose: Transurethral incision of the prostate is a well established technique for relieving bladder outflow obstruction caused by prostate glands less than 30 gm. We present data showing that the holmium:YAG laser can prevent postoperative catheterization without compromising the outcome of surgery. Materials and Methods: We prospectively followed 100 men an average of 62 years old with symptomatic bladder outflow obstruction and a benign prostate gland less than 30 gm. clinically in whom serum prostate specific antigen was less than 4 mu g./l. They were assessed using International Prostate Symptom Score, urinary flow rate, post-void residual estimation and sexual function questionnaires preoperatively, and 6 weeks, and 1 and 2 years postoperatively. With the patient under general anesthesia a single incision was made from the ureteral orifice to the verumontanum and out to fat using holmium:YAG laser energy transmitted through a 400 nm. fiber sheathed in a ureteral catheter. Results: A total of 97 patients voided without postoperative catheterization. Average International Prostate Symptom Score decreased from 19.2 to 3.7 at 6 weeks and it remained improved at 2 years (average 3.5). Reciprocal results were achieved with improvement in average urinary flow rate from 9.79 to 19.23 and 18.27 mi. per second at 6 weeks and 2 years, respectively. Residual urine measurement decreased from 133.6 mi. preoperatively to 27 and 10 mi. at 6 weeks and 2 years, respectively. All 77 patients potent preoperatively remained so, although retrograde ejaculation developed in 8. Conclusions: The holmium:YAG laser allows transurethral prostatic incision to be performed without the need for postoperative catheterization while maintaining efficacy.