Urinary tract infection is a common bacterial disease that presents during childhood and may lead to renal scarring. Several studies have shown a strong association between the angiotensin converting enzyme (ACE) deletion polymorphism and renal scarring in children with vesicoureteric reflux (VUR). The purpose of this study was to investigate the possible correlation between the ACE deletion polymorphism and renal scarring in 186 children with urinary tract infection (UTI), of whom 90 were renal scar positive and 96 were renal scar negative. The control group consisted of 129 children with no UTI. Renal scars were diagnosed by means of (99m)Tc-dimercapto-succinic acid scans, and ACE genotypes were determined as II, ID, and DD by PCR analyses. The ACE genotype distribution was 10% II, 67% ID, and 23% DD in the renal scar-positive group, 18% IotaIota, 42% ID, and 40% DD in the renal scar-negative group, and 22% II, 47% ID, and 31% DD in the control group. No correlation was found between the DD genotype and renal scar formation in children with UTI. The same results were obtained following strafication of the patients by VUR and age of the first urinary tract infection. In conclusion, the results of this study suggest that the DD genotype is not an independent risk factor for renal scarring in children with UTI.