The aim of our study was to evaluate whether neutrophil-to-lymphocyte ratio (NLR) is a predictor of disease progression and recurrence in patients with primary non-muscle-invasive bladder cancer (NMIBC). This was a prospective study of 86 patients with newly diagnosed NMIBC. The patients were classified by the number of points assigned by the European Organization for Research and Treatment of Cancer risk tables. The correlation between progression score, recurrence score, age, mean platelet volume, red blood cell distribution width and NLR was assessed statistically. The same parameters were compared between the risk groups. A significant difference in NLR and age values was observed between recurrence and progression risk score groups. The relationships between NLR and recurrence and progression risk scores were no longer significant after correcting for the statistical effect of age on scores. Age was significantly different between groups after adjusting for NLR. Our study revealed that NLR and age were associated with patient age and bladder tumor progression and recurrence risk scores. After correcting for age, the significant relationship with NLR was lost, in contrast to some previous studies. We recommend that patient age should be corrected to avoid misleading results in NLR studies. Copyright (C) 2016, Kaohsiung Medical University. Published by Elsevier Taiwan LLC.