CSN6 is a subunit of the constitutive photomorphogenesis 9 (COP9) signalosome (CSN). CSN is involved in cellular and developmental processes such as signal transduction, transcriptional activation, cell cycle control, and tumorigenesis. CSN6 is highly expressed in several human cancers, including colorectal cancer, and breast cancer. However, no previous research has elaborated on the relationship between CSN6 expression and survival in patients with upper tract urothelial carcinoma (UTUC). Therefore, the purpose of this study is to evaluate the clinical significance of CSN6 in UTUC. CSN6 expression in 89 patients with UTUC enrolled in this study was examined using immunohistochemistry. The associations between CSN6 expression and clinicopathological variables were analyzed. CSN6 expression was significantly correlated with patients with high pathological stage (P = .006), male gender (P = .025), and high serum creatinine levels (P = .014). In univariate and multivariable analysis, high CSN6 expression was associated with a higher bladder recurrence (P = .005) and poor cancer‐specific survival (P = .001) for UTUC. In conclusion, CSN6 expression is a potential biomarker for predicting cancer recurrence and clinical survival in UTUC. Further research is necessary to investigate its role in the progression of UTUC.