Of patients undergoing renal transplantation during a recent 18-month period 42 per cent had significant urologic abnormalities. A thorough pre-transplant evaluation is especially critical in these patients. Massive reflux is an indication for pre-transplantation nephroureterectomy. Reconstructive operations provided a functional bladder in some patients who had previously undergone urinary diversion. Other patients required formation of intestinal conduits. Suggestions for the management of transurethral prostatectomy in patients with renal failure are outlined. Patients with a variety of abnormalities of the urinary tract had a transplantation success rate comparable to that of azotemic patients with normal urinary systems.