Two hundred and one urological complications have been diagnosed and treated in 123 transplant recipients in a series of 1000 consecutive renal transplant operations (overall incidence 12.5%). Obstructive uropathies and urinary fistulae accounted for 95% of these complications and all of the mortality (22%). Details of management and patient and graft survival are given. A relationship between mortality from a urological complication and steroid dosage was found. A 30% incidence of recurrent or secondary urological complications was also noted with correspondingly worsened prognosis. Early diagnosis followed by early aggressive surgical treatment is advocated.