Metabolic syndrome (MetS) has been reported to be associated with adverse outcomes in cancer patients. However, the relationship between MetS and upper tract urothelial carcinoma (UTUC) has yet to be explored. To investigate the prognostic value of MetS in UTUC after radical nephroureterectomy. A total of 644 patients with UTUC after radical nephroureterectomy were identified at West China Hospital from May 2003 to December 2016. MetS was defined as the co-existence of 3 or more of 5 components (obesity, hypertension, elevated fasting glucose, decreased high-density lipoprotein-cholesterol, and hypertriglyceridemia). Logistic and Cox regression analyses were performed to evaluate the associations of MetS with pathological features and survival outcomes. Decision curve analysis and Harrell concordance index were used to determine the clinical utility of the prediction models. Of 644 patients, 157 (24.4%) had MetS. Over a median follow-up of 39 months, 269 (41.8%) experienced disease recurrence, 233 (36.2%) died, and 185 (28.7%) died of UTUC. MetS was independently associated with high-grade disease, advanced pT stage (≥pT3), and lymphovascular invasion (each P < 0.05). Multivariate Cox regression analysis showed that MetS was an independent factor for decreased cancer-specific survival (hazard ratio [HR]: 1.38, 95% confidence intervals [CI]: 1.01-1.89, P = 0.042) but not for recurrence-free survival (HR: 1.27, 95% CI: 0.97-1.67, P = 0.078), and overall survival (HR: 1.24, 95% CI: 0.95-1.62, P = 0.121). The estimated c-index of the multivariate models for cancer-specific survival was 0.763 compared with 0.769 when MetS added. MetS is a negative prognostic factor in UTUC. Further studies of MetS in UTUC are demanded. Copyright © 2018. Published by Elsevier Inc.