Fendereski K, Nabighadim A, Seyedtabib M, et al. - In the present study, the researchers sought to assess and compare the effectiveness of urinary carbohydrate antigen 19-9 (CA19-9), neutrophil gelatinase–associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) biomarkers as predictive factors to evaluate the need for surgery in patients with ureteropelvic junction obstruction. Urine samples were obtained from 161 patients at diagnosis and assessed their levels of the three biomarkers. There were 60 male and 22 female patients with a mean age of 21 months in the non-surgery group. The surgery group consisted of 58 boys and 21 girls with a mean age of 26.9 months, with no significant age and gender disparity between the two groups. Evaluations indicate the higher effectiveness of CA19-9 to predict the need for surgical intervention relative to the other biomarkers, as well as a significant association between kidney function deterioration and urinary CA19-9 and NGAL. In addition to future studies determining the relationship between markers and kidney fibrosis, the findings of this investigation may pave the way for more extensive clinical application of these urinary biomarkers.