PURPOSE: We aimed to evaluate the ability of the advanced lung cancer inflammation index (ALI) to predict the prognosis of patients who underwent radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). We also aimed to compare the ALI with other inflammatory or nutritional indices as prognostic indicators. METHODS: We retrospectively evaluated patients who underwent RNU for UTUC at multiple centers between January 2010 and April 2024. We calculated the ALI before RNU and divided the patients into the low ALI and high ALI groups. We used 1:1 propensity score matching (PSM) to adjust the clinicopathological differences between two groups. We compared the overall survival (OS) and recurrence-free survival (RFS) of the low and high ALI groups using the Kaplan-Meier method. Furthermore, we assessed the ALI as a predictor of OS and RFS using a multivariate Cox proportional hazards regression analysis. RESULTS: Of 488 patients (48.3% low ALI group), 160 patients from each group were matched. The Kaplan-Meier analysis revealed that the OS (p = 0.009) and RFS (p = 0.006) of the low ALI group were significantly shorter than those of the high ALI group. According to a multivariate analysis that included clinicopathological prognostic indicators, a low ALI was an independent predictor of poor OS (p = 0.014) and RFS (p = 0.038). Furthermore, according to the multivariate analysis including other inflammatory or nutritional indices, the ALI was an independent predictor of poor OS (p = 0.024) and RFS (p = 0.044). CONCLUSIONS: The ALI was a significantly useful prognostic predictors of patients with UTUC who underwent RNU.