Introduction: There is some evidence to suggest that low levels of uromodulin in urine and serum are associated with decreased renal function and increased mortality risk.

Objectives: This study is designed to measure circulating uromodulin levels and explore their relationship to urinary tract infection and renal function in kidney transplant recipients.

Patients and Methods: In this cross-sectional study, 90 eligible kidney transplant recipients were evaluated 6–12 months of post-transplantation. Fasting blood samples were taken to determine the serum level of uromodulin with urea, creatinine, and other biochemical characteristics. Urine samples were taken for analysis and culture. Kidney function was estimated based on the chronic kidney disease epidemiology collaboration (CKD-EPI) creatinine equation and the modification of diet in renal disease (MDRD) equation.

Results: Patients’ serum uromodulin levels were significantly correlated with their serum creatinine (P = 0.024) and estimated glomerular filtration rate by the EPI equation (eGFR-EPI, P = 0.038). There was no significant association between serum uromodulin levels and incidence of urinary tract infection of post-transplantation (P > 0.05).

Conclusion: Serum and urine uromodulin levels may be regarded as the predictive indicators of renal function. However, given the lack of studies on the association between serum uromodulin levels and urinary tract infection risks in kidney transplant recipients, further research is needed to clarify uromodulin’s protective effect against urinary tract infection.