['Higher chronological age has been suggested to confer worse prognosis in patients with upper tract urothelial carcinoma (UTUC). The aim of the current study was to test this hypothesis in a large multicenter external validation cohort of patients treated with radical nephroureterectomy (RNU) while controlling for patient performance status.', 'We retrospectively reviewed the data from 1,169 patients treated with RNU for UTUC. Age at RNU was analyzed both as a continuous and categorical variable (<50\xa0years, n\xa0=\xa066; 50-59.9\xa0years, n\xa0=\xa0185; 60-69.9\xa0years, n\xa0=\xa0367; 70-79.9\xa0years, n\xa0=\xa0419; ≥80\xa0years, n\xa0=\xa0132). Median follow-up was 37\xa0months.', 'Actuarial recurrence-free, cancer-specific, and all-cause survival estimates at 5\xa0years after RNU were 69, 73, and 61%, respectively. Advanced age was associated with female gender, higher ECOG status, higher ASA score, and a lower probability of receiving adjuvant chemotherapy (all P values\xa0≤\xa00.02). In multivariable analyses, advanced age was associated with decreased recurrence-free (P\xa0=\xa00.021), cancer-specific (P\xa0=\xa00.002), and all-cause survival (P\xa0<\xa00.001) after controlling for the effects of gender, tumor location, number of lymph nodes removed, tumor grade, stage, architecture, necrosis, and lymphovascular invasion. After addition of ECOG status, age remained an independent predictor of only all-cause mortality (P\xa0>\xa00.001).'] Is chronological age an independent predictor of clinical outcomes after radical nephroureterectomy?