Aim: The purpose of this study was to investigate the prognostic role of pretreatment Prognostic Nutritional Index (PNI) in metastatic renal cell carcinoma (mRCC) patients given pazopanib or sunitinib as first-line targeted therapy. Materials and Methods: We retrospectively analyzed the treatment modalities, demographic, clinical, and pathological features of 77 patients with mRCC, and calculated prognostic nutritional index. Based on the median value, patients were grouped as those having low and high PNI values. The Kaplan-Meier method was used for survival analysis, and Cox-regression analysis was used for univariate and multivariate analyses. Results: The overall median progression-free survival (PFS) and overall survival (OS) time for all patients were 15 months [95% confidence interval (CI): 10.9-19.1 months] and 27 months (95% CI: 15.9-38.1 months), respectively. Patients with low PNI had significantly shorter median PFS (11 vs 20 months, p=0.001) and OS (17 vs 40 months, p=0.001) than those with high PNI. In multivariate analysis, PNI was shown as an independent predictor on both OS and PFS. Moreover, Eastern Cooperative Oncology Group-Performance Status was shown as an independent predictor for OS and International Metastatic Renal-Cell Carcinoma Database Consortium-score for PFS. Conclusion: Low PNI could be a significant prognostic marker for survival in mRCC patients who have received tyrosine kinase inhibitors as first line target therapy.