To investigate angiotensin-converting enzyme (ACE) gene deletion/insertion (D/I) polymorphism as a risk factor of renal scarring in children, we determined ACE genotypes in 63 paediatric patients with primary vesicoureteric reflux (VUR) grade I-V and recurrent urinary tract infections (UTI). Renal cortical scars were evaluated applying Technetium-99-m-unithiol SPECT method in 21 children. No statistically significant differences were found in allele and genotype distribution of the D/I polymorphism within ACE gene between children with VUR/UTI and healthy Caucasians (n = 806, after meta-analysis of literature data) (D allele frequencies--47% vs 54%, respectively). It suggests that ACE gene polymorphism is not associated with primary VUR. Renal scarring was revealed in 7 out of 21 children and there was also no statistically significant difference in D/I distribution between scar (n = 7) and non-scar (n = 14) subgroups of patients and controls. However, higher incidence of D allele (64%) in children with renal parenchymal damage could suggest the hypothesis that this genetic factor plays an important role in renal scarring. Therefore, to verify this assumption further studies on a larger group of patients are needed.