C-reactive protein (CRP) is an independent prognostic factor for renal cell carcinoma (RCC). The aim of the present study was to investigate the overall prognostic impact of CRP in patients with metastatic RCC treated with sorafenib. Between April 2008 and December 2014, 40 consecutive patients with metastatic RCC were treated with sorafenib at our institution. The patients were divided into two cohorts according to the pretreatment CRP level: (i) a normal CRP cohort (≤0.30 mg/dl) and (ii) an elevated CRP cohort (>0.30 mg/dl). Kaplan–Meier overall survival analysis was carried out. The effects of selected variables on survival were assessed by multivariate regression using the Cox proportional hazards model. The normal CRP cohort included 16 patients (40.0%) and the elevated CRP cohort included 24 patients (60.0%). The normal CRP cohort showed significantly longer overall survival than the elevated CRP cohort (median, 52.0 vs. 17.0 months; P=0.0072). On multivariate analysis, normal CRP predicted longer overall survival (hazard ratio, 0.367; 95% confidence interval, 0.147−0.914; P=0.0313). Pretreatment normal CRP predicted better overall survival in patients with metastatic RCC treated with sorafenib and CRP level may be a useful biomarker for predicting overall survival of patients treated with sorafenib.