Chronic allograft nephropathy (CAN) is the leading cause of longterm renal transplant loss. Angiotensin-II may play a role in the development and progression of CAN. Angiotensin converting enzyme inhibitors (ACEI) comprise a drug class that inhibit the effects of angiotensin-II. However these drugs have been reported to cause elevated potassium and creatinine levels in some renal transplant patients. Yet, there are now several retrospective reports of long term benefits of improved renal function and graft survival in renal transplant recipients. There have been no reports of prospective randomized controlled trials of ACEI in renal transplant patients in the early post transplant period.