Background. Chronic allograft dysfunction (CAD), the major cause of the failure of kidney allografts, may be caused by immunological and non-immuno logical haemodynamic factors. Renin-angiotensin system has been implicated in the development of intraglomerular hypertension and has a central role on progression in chronic renal disease. Polymorphism in 16th intron of the ACE gene has been reported to predict the circulating angiotensin 11 levels. The aim of this study was to investigate the effect of the both recipient and donor angiotensin converting enzyme (ACE) genotype on the development of CAD in renal allograft recipients.