45 patients underwent urinary diversion by caecocystoplasty following simple or radical cystectomy with or without prostatectomy. The immediate postoperative course of such a major operation was surprisingly simple both in terms of the gastrointestinal tract (due to the use of automatic sutures) and in terms of the urinary tract. Micturition and diurnal continence were perfect. The few cases of incontinence related to high caecal pressure were controlled by perineal reeducation and/or the prescription of oxybutynin. A Peniflow apparatus controls the inevitable enuresis of these neobladders when the trigone has not been preserved. The upper tract is perfectly protected. The authors consider that the caecal reservoir warrants a place of choice in bladder replacement after cystectomy.