Back in 1983 we created a continent urinary reservoir, called the MAINZ pouch, using 10 to 15 cm. of cecum as well as two terminal ileal segments of equal length. Following detubularization, the posterior wall of the pouch is established by anastomosis of the ascending colon with the terminal ileal loop starting at the inferior aspect. The latter is then anastomosed with the next proximal ileal segment. The ureters are implanted in an antirefluxive manner in the open end technique through a submucosal tunnel of 4 to 5 cm length. For bladder augmentation the pouch is anastomosed to the bladder remnant. For bladder substitution a buttonhole incision at the most inferior aspect of the cecal pole is placed or the appendix is used for end-to-end anastomosis to the membranous urethra. For continent diversion an additional 7 to 12 cm of ileum are isolated in order to create an ileal intussuscepted valve. Alternatively the appendix can be used. Continence is achieved by submucosal embedding of the appendix into the cecal pole. A total of 346 patients underwent the MAINZ pouch procedure in Mainz and Wuppertal; 56 for bladder augmentation, 49 for bladder substitution and 241 for continent urinary diversion. We encountered early complications in 29 of the 346 patients (8.38%). Late complications were observed in 72 patients (20.8%). The major complications we encountered were stone formation inside the pouch in 19 patients and stomal stenosis in 21. 54 of the 56 patients with a bladder augmentation are completely continent (mean follow-up: 50 months, range: 10 to 83 months). All of the 49 patients who received a bladder substitution after radical cystectomy are continent during daytime. Three of these patients who do not empty their bladder at regular four hour intervals have leakage during the night (follow-up: 23 to 69 months). The revision rate due to nipple gliding and subsequent incontinence could be greatly reduced by the use of staples for fixation of the ileal nipple and the use of the appendix. For correction of the most frequently occurring complications standardized techniques have been developed.