Transforming growth factor beta-1 (TGF-β1) is a peptide of low molecular weight and has pleiotropic action. In the kidneys, it stimulates fibrogenesis through enhanced production of ECM proteins. The aim of this study is to measure the level of TGF-β1 in serum and urine of children with different grades of vesicoureteric reflux (VUR) and to assess its diagnostic significance in the diagnosis of VUR. It has been found that serum TGF-β1 level in children with VUR was significantly higher than that in control children. In addition, serum TGF-β1 level in children with grade IV-V VUR was significantly higher than that in children with grade III VUR, which in turn was significantly higher than that in children with grade II VUR. Thus, serum TGF-β1 level could be used in the diagnosis of the VUR. In addition, serum TGF-β1 level has also a prognostic value as it correlates well with the gradient of the VUR.