To identify the impact of albumin-globulin ratio (AGR) on pathologic and survival outcomes in patients with upper tract urothelial carcinoma (UTUC) after radical nephroureterectomy (RNU). We retrospectively reviewed medical records of 620 patients treated with RNU for UTUC at our institution. Logistic regression analysis was used to evaluate the relation between low AGR (<1.45) and adverse pathologic features. Kaplan-Meier curves were used to estimate recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) probabilities between 2 groups. Univariable and multivariable Cox regression models were performed to address prognostic factors related to RFS, CSS, and OS. Of the 620 patients, 323 (52.1%) had AGR < 1.45. During a median follow-up of 50.0 months (interquartile range, 28-78 months), 277 (44.7%) experienced disease recurrence and 194 (31.3%) died of disease. The results showed that low AGR was significantly associated with adverse pathologic features (all P < .05). Kaplan-Meier analysis showed that compared to those with high AGR (≥1.45), patients with low AGR had poorer RFS, CSS, and OS (P < .001). After adjusting for the confounding clinicopathologic factors, multivariate analyses showed that AGR < 1.45 independently predicted poor RFS (hazard ratio [HR] = 1.321, P = .029), CSS (HR = 1.503, P = .010) and OS (HR = 1.403, P = .015). Low preoperative AGR is an independent predictor of worse pathologic and oncologic outcomes in patients with UTUC after RNU. The application of AGR as an easily assessed blood-based biomarker in predicting the prognosis of patients with UTUC is promising. Copyright © 2018 Elsevier Inc. All rights reserved.