BACKGROUND This study aimed to evaluate the factors associated with a survival benefit for patients with metastatic renal cell carcinoma (mRCC) treated with sunitinib, with and without cytoreductive nephrectomy (CN). MATERIAL AND METHODS This retrospective clinical study included 118 patients with mRCC who were treated with CN and sunitinib (CN-sunitinib) (N=70) and with sunitinib-alone (N=48). Categorical clinicopathological variables were compared with hypothesis tests using contingency tables and a chi-squared test. Independent indicators for progression-free survival (PFS) and overall survival (OS) were analyzed with univariate and multivariate Cox regression models. The Kaplan-Meier method and log-rank test were used to evaluate patient survival. RESULTS The median PFS and OS for the 118 patients were 8.38 and 15.48 months, respectively. There were no significant differences between the CN-sunitinib group and the sunitinib-alone group for either PFS (7.2 months vs. 11.6 months; P=0.525) or OS (16.7 months vs. 15.2 months; P=0.839). Stratification of patients based on clinicopathological characteristics showed that CN was significantly associated with reduced PFS and OS for patients with lymph node metastasis (PFS, P<0.001; OS, P<0.001) and high International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk scores (PFS, P=0.003; OS, P=0.011). However, CN was associated with a significant survival benefit for patients with low levels of serum C-reactive protein (CRP<10 mg/L) (PFS, P=0.026; OS, P=0.007). CONCLUSIONS Sunitinib-alone without CN improved the survival of patients with mRCC who had high IMDC risk scores or lymph node metastasis. CN and sunitinib resulted in significantly improved survival in patients with low serum CRP.