Aim. Vesicoureteral reflux (VUR) is one of the most common conditions seen in pediatric urology. Fortunately, there are many treatment options for this disorder. The grading system for VUR varies among doctors, and the literature on its reliability is sparse. Here, we assessed the effectiveness of the current VUR grading system. Methods. A series of 40 voiding cystourethrogram (VCUG) studies were selected. Four pediatric urologists (PU) and four pediatric radiologists (PR) independently graded each VCUG and then agreed on a uniform interpretation. For statistical analysis the intraclass correlation coefficient (ICC) was applied to assess interrater agreement. Results. ICC values ranging from 0.82 to 0.88 reflected the strong reliability of VCUG for grading cases of VUR among pediatric urologists and radiologists as separate groups, and the reliability between the two groups was also good, as indicated by an ICC of 0.89. Despite the high ICC, disagreement existed between raters; the lowest agreement was associated with middle grades (III and IV). Conclusions. The interrater reliability of the international grading system for VUR was high but imperfect. Thus, grading differences at middle grades can profoundly influence the type of treatment pursued.