INTRODUCTION The rectum-urethral fistula is one of the most seriously complications of radical prostatectomy. It´s produced by direct injury of rectum or thermical damage. There are some techniques for repair it, but the probability of recurrence is hight. MATERIAL AND METHODS We show a surgical procedure for repair urethro-vesical fistula that consists in a perineal approach, dissect the rectum-urethral space until identify the the fistula. Previously we performed endoscopy , catheterize both ureters and if is it possible the urethral orifice. After suture rectum and urethra the gracilis muscle of the leg is separated from its distal insertion, and we mobilize it an place it between rectum and bladder. This technique give us a very thick flap and difficults the likelihood of recurrence. RESULTS We performed this procedure in five cases of rectum-urethral fistula: three laparoscopic radical prostatectomy, one open prostatectomy, and one after open prostatectomy and radiotherapy. In all cases except open prostatectomy colostomy was performed.. In four cases, with minimum follow-up of six months the fistula was resolved. Only in the patient treated with radioteraphy persists a little leakage in TC from urinary tract to rectum without simptomatology. CONCLUSIONS The technique of gracilis muscle flap has good results for repair this kind of fistula. The reason of its effectivity is the excellent vitality of the flap due to its proximal irrigation, the possibility of a very good mobilization of the flap, and the thickness of the tissue.