Background : The platelet–lymphocyte ratio (PLR) and neutrophil–lymphocyte ratio (NLR) have been reported as prognostic factors in various cancers, but their roles in metastatic renal cell cancer (mRCC) remain unclear. We investigated the significance of PLR and NLR, along with that of established prognostic factors, in mRCC patients receiving first-line tyrosine kinase inhibitors (TKI). ; Methods : Data obtained from 63 mRCC patients who received first-line TKI between 2007 and 2013 were evaluated retrospectively. The association of PLR, NLR, and established prognostic factors with progression-free survival (PFS) and overall survival (OS) was analyzed using the Kaplan–Meier method. The influence of independent prognostic factors on survival was determined using multivariable Cox regression analysis. ; Results : High NLR (>3.6) and PLR (>150) were related to shorter PFS (p = 0.001) and OS (p = 0.001). The presence of brain metastases [hazard ratio (HR) 4.94, 95% CI 1.75–13.9; p = 0.002] and high PLR (>150, HR 13.1, 95% CI 5.14–33.2; p = 0.001) were independently associated with PFS, and Eastern Cooperative Oncology Group Performance status ≥2 (HR 3.60, 95% CI 1.39–9.31; p = 0.008), lymph node metastasis (HR 2.76, 95% CI 1.11–6.86; p = 0.029), brain metastasis (HR 9.39, 95% CI 2.74–32.1; p = 0.001), and high PLR (>150, HR 16.1, 95% CI 4.41–58.4; p = 0.001) with OS. ; Conclusions : High PLR was associated with shorter survival of mRCC patients receiving first-line TKI. The PLR may be an effective independent prognostic factor in this setting.