The purpose of this study was prospectively evaluate the ability of Neutrophil-to-Lymphocyte ratio (NLR) to predict disease progression in patients with non-muscle invasive bladder cancer (NMIBC). This is a continuation of our previous retrospective study that indicated the significance of NLR $>$ 2.5 criterion as a predictor of progression in patients with NMIBC. Since December 2013, all patients admitted to Bnai-Zion department for TUR-BT and agreed to participate in the study, had blood analyses for cell count and differential 24hr prior to surgery. Patients with pathological NMIBC were followed prospectively for disease progression. The end-point of the follow up was either a disease progression or the termination of the study. Kaplan-Meier curves and Cox regression were performed to assess the predictive ability of NLR $>$ 2.5 for disease progression. Our results demonstrate a significant difference ($p = $ 0.02) in mean progression-free survival - (35.9 months vs 41.1 months) in the whole cohort Kaplan-Meier survival plot factored by NLR $>$ 2.5. Mean progression-free survival of NLR $>$ 2.5 stratified by stage, grade and treatment (sub-group analysis), showed statistical significance ($p =$ 0.035) for those treated with intra-vesical instillation, and demonstrated a persistent trend for the rest of the stratifications - revealing that the NLR $>$ 2.5 groups always fared worse than the NLR $<$ 2.5 groups. In a univariate analysis, whole cohort Cox regression analysis for disease progression, NLR $>$ 2.5 was found significant ($p =$ 0.05; HR 7.8; CI 1-61), indicating that the probability of progression is increased at least 7-fold for a person with a NLR $>$ 2.5 compared with those with NLR $<$ 2.5. In conclusion, NLR $>$ 2.5 was found to be a significant predictor of disease progression and demonstrated high hazard ratio and worse progression-free survival in patients with NMIBC, especially in those treated with intra-vesical instillation. We propose to consider the incorporation of NLR $>$ 2.5 in the next revisions of the European Organization for Research and Treatment of Cancer (EORTC) scores, given more widely available evidence.