Urinary diversion via a continent ileal reservoir has been performed in 12 patients. An isolated ileal reservoir was constructed using the technique described for patients with a continent ileostomy. The ureters were implanted into an afferent segment provided with a reflux-preventing nipple valve. There were few operative complications and no operative mortality. Late complications involving malfunction of the nipple valves occurred in 8 patients and were corrected surgically. Postoperative followup presently is between 9 months and 6 1/2 years. Two patients have died: 1 in an accident and 1 of metastatic bladder carcinoma. The remaining 10 patients are continent and without reflux to the upper urinary tract. The reservoir generally is emptied by intermittent self-catheterization between 3 to 6 times daily. The volume capacity of the reservoir is more than 500 ml. Urinary cultures have been constantly negative in 7 patients and the contents of the reservoir more or less permanently contained bacteria in 5. Dilatation of the upper urinary tracts, progressive renal deterioration or metabolic disturbances have not been encountered. All patients are satisfied with this type of urinary diversion, especially those who have undergone other types of diversion previously.