Ileal urinary diversion has been carried out on 8 occasions in 7/215 kidney transplant patients. In six instances the diversion was required either because the bladder had previously been removed or there was gross abnormality of the outflow tract: in 2 it was successfully employed to deal with difficult post-transplantation urinary fistulae. 4 patients died: 3 within 2 months and 1 at 9 months after the operation. Infection with organisms indistinguishable from those cultured from the ileal loop, was a common complication and, although there were other significant factors which contributed to the mortality, retrospective consideration suggests that energetic prophylactic antibacterial therapy should be instituted when kidney transplantation with ileal urinary diversion is undertaken.