An isolated segment of ileum, its caliber reduced by excising a longitudinal strip from its antimesenteric border, can be used to supplement or replace the ureter in establishing flow from the kidney to the bladder or the skin. Benefits from this ileal-conduit diversion are increasingly evident when the operation is reserved for especially selected patients. In 45 of the present series of 70 patients the underlying disease was benign; 16 patients were less than 25 years old. Eight cases are presented in support of the thesis that success in the use of the ilealconduit operation must be measured in terms of symptomatic relief, general sense of well-being, ability to resume a place in society, and anticipated longevity.