Purpose:To investigate the prognostic impact of postoperative neutrophil to lymphocyte ratio (NLR) on survival outcomes in upper urinary tract urothelial carcinoma (UTUC).Materials and methods:Data from 397 patients with UTUC who underwent radical nephroureterectomy (RNU) without a history of neoadjuvant chemotherapy between 2002 and 2017 were retrospectively analyzed. Based on a postoperative NLR cut-off of 3, patients were divided into low NLR (<3) or high NLR (≥ 3) groups. After 2:1 propensity score matching, a Kaplan-Meier with log-rank test was used to compare survival outcomes between the two groups. Univariate and multivariate Cox proportional hazard models were used to investigate the impact of the postoperative NLR on survival outcomes.Results:The matched cohort (n=176) consisted of 116 low NLR and 60 high NLR patients. The Kaplan-Meier curves showed significant differences in the 3- and 5-year overall and cancer-specific survival rates between the two groups (eachp= 0.03). Multivariate Cox regression analysis revealed that a postoperative high NLR was an independent predictor of worse overall survival (hazard ratio [HR]:2.13; 95% confidence interval [CI]:1.18-3.85,p= 0.012) and cancer-specific survival (HR:2.16; 95% CI 1.11-4.21,p= 0.024).Conclusions:Propensity score matching analysis revealed postoperative high NLR can be considered a potential inflammatory biomarker for predicting survival outcomes of UTUC patients treated with RNU.