Early determination of renal scar development risk in children following first urinary tract infection (UTI) and early detection and treatment of vesicoureteral reflux (VUR) are important to prevent renal functional impairment. The aim of this study was to determine the prevalence of VUR and associated renal scar formation, in children who had acute pyelonephritis (APN), first afebrile UTI, and recurrent afebrile UTIs. Patient records of 642 children having UTI were scrutinized and 278 out of 642 were enrolled in this study. The patients were divided into three groups: Group 1, patients with APN (n = 73); Group 2, patients with the first afebrile UTI (n = 88); and group 3, patients with recurrent afebrile UTIs (n = 117). Among these groups, VUR prevalence did not differ significantly (group 1: 24.6%, group 2: 22.7%, and group 3: 26.4%. Renal scarring was detected in 19.3% of the patients and was remarkably lower in group 2 when compared with the other two groups (P <0.05). Renal scarring was found in 37.1% of the patients with VUR, whereas it was found in 14.3% of patients without VUR. Renal scarring incidence was remarkably higher in patients with grades 4-5 VUR (61.5%) compared with those with grades 1-3 VUR (30.6%) (P = 0.055). In conclusion, since VUR was demonstrated in as many as one-quarter of patients with the first afebrile UTI and VUR incidence did not differ significantly among the groups, all UTIs, lower and upper ones, should be carefully evaluated. © Springer Science+Business Media, B.V. 2009.