Background. Urine culture, gold standard of urinary tract infection (UTI), takes time. Alternative parameters are needed. Neutrophil–lymphocyte ratio (NLR) can be counted from complete bloodtests. This study aimedto determine the NLR as bacteria–caused UTI marker in children.

Methods. A cross sectional study in 50 patients with suspected UTI and leukocyturia in Adam Malik and USU Hospital Medan, September 2017 to January 2018. Urine culture and NLR were taken from all patients. NLR cut off point was determined based on the receiver–operating characteristic (ROC) curve, with p–value <0.05 was significant.

Results. Positive urine culture was found in 35 children (70%) with suspected UTI and leukocyturia. ROC analysis showed NLR insignificant to be used as bacteria–caused UTI marker (p = 0.073). Cut off point of NLR for bacteria–caused UTI was 4.55, with area under curve 0.665 (CI 95%: 0.515–0.815).

Conclusion. NLR cannot be used as bacteria–caused UTI marker in children.