Purpose: The prognostic role of the controlling nutritional status (CONUT) score in renal cell carcinoma (RCC) has not been evaluated. The aim of the current study was to clarify the prognostic significance of the CONUT score in Korean patients with surgically treated RCC.Materials and methods: A database of 1,881 patients with surgically treated RCC from a multiinstitutional Korean collaboration between 1999 and 2015 was analyzed. The preoperative CONUT score was calculated from serum albumin, total cholesterol concentrations, and total lymphocyte count. Clinicopathological variables and survival rates were compared between the CONUT score groups.Results: A high CONUT score was associated with older age, lower body mass index, lower preoperative prognostic nutritional index, and presence of diabetes or hypertension (each P < 0.001). Regarding pathologic features, a high CONUT score was associated with aggressive tumor characteristics including large tumor size, advanced stage, high nuclear grade, lymphovascular invasion, and sarcomatous differentiation (each P < 0.001). Multivariate Cox regression analysis indicated that a high CONUT score (≥ 2) was an independent predictor of cancer-specific mortality (hazard ratio, 1.892; 95% CI: 1.118–3.201; P = 0.018).Conclusion: The CONUT score, an easily measurable immune-nutritional biomarker, may provide useful prognostic information in patients with surgically treated RCC.