PURPOSE: The aim of this study was to determine the impact of the preoperative creatinine-cystatin C ratio (CCR) on the survival prognosis of patients following radical nephrectomy (RNU) for upper tract urothelial carcinoma (UTUC). METHODS: The retrospective analysis was conducted on UTUC patients who underwent radical nephrectomy (RNU) at West China Hospital between January 2009 and December 2019. The endpoint of the study was cancer-specific survival (CSS). Kaplan-Meier curves were used to estimate survival, and Cox proportional hazards modelling was used to assess risk. Nomograms were developed to predict CSS at 3 and 5 years of age, and the predictive power was assessed. RESULTS: A critical CCR of 59.61 µmol/mg was demonstrated to affect 504 patients with UTUC who had undergone RNU. A correlation was identified between a lower preoperative CCR and a considerably worse CSS. In patients with UTUC, CCR was identified as an independent risk factor for CSS, particularly in patients with locally advanced UTUC (pT ≥ 3) (HR: 1.84, 95% CI: 1.14, 2.97). Moreover, the CCR-based nomogram exhibited robust predictive capacity, with areas under the curve for the 3- and 5-year CSS reaching 0.823 and 0.793, respectively. CONCLUSION: Preoperative CCR is an independent predictor of CSS in UTUC patients receiving RNU treatment. As such, it should be viewed as a potentially useful customized tool in therapeutic decision-making.