BACKGROUND/AIMS: Emerging studies have shown that the neutrophil-lymphocyte ratio (NLR) is a potential predictor in various tumors. Our study was conducted to assess the prognostic value of the pretreatment NLR in bladder cancer and metastatic or unresectable urothelial carcinoma (mUC or uUC) patients up to July 2017. The correlation between the pretreatment NLR and pathological characteristics was also evaluated in bladder cancer patients. METHODS: The hazard ratio (HR) and odds ratio (OR) with the 95% confidence interval (CI) were extracted or calculated from the included studies for further pooled analysis. A total of 21 studies were included in a pooled analysis. RESULTS: The pooled results indicated that a high pretreatment NLR was associated with reduced overall survival (OS) (HR=1.27, 95% CI=1.12-1.43), relapse-free survival (RFS) (HR=1.41, 95% CI=1.23-1.60), progression-free survival (PFS) (HR=1.75, 95% CI=1.36-2.15), disease-specific survival (DSS) and cancer-specific survival (CSS) (HR=1.27, 95% CI=1.19-1.35) in the bladder cancer patients. Additionally, an elevated pretreatment NLR suggested a worse OS rate in the mUC or uUC patients (HR=1.63, 95% CI=1.34-1.91). The pooled ORs and 95% CIs showed that a high pretreatment NLR could be a risk indicator for certain pathological features, such as lymphovascular invasion, a positive margin status and advanced tumor stage. CONCLUSIONS: our results showed that a high pretreatment NLR predicted poor prognosis in bladder cancer, mUC and uUC patients.