The authors report the fourteenth case of rectourethral fistula associated with Crohn's disease, in a 53-year-old man with a 20-year history of ileocolonic Crohn's disease. The patient developed a rectourethral fistula following an episode of complex anoperineal suppuration surgically exposed on several occasions. Repeated surgical exposure and urine drainage were not sufficient to close the fistula and cure the perineal suppuration. After 10 months, the patient was treated by the rectal mucosal transposition flap technique to close the rectal aspect of the fistula, which ensured cure of the patient's fistula and anoperineal lesions. This technique has been used successfully on 4 occasions and appears to be an effective treatment for rectourethral fistula in Crohn's disease with healthy rectal mucosa.