Background. Renal cell carcinoma is the most common type of kidney cancer. Taking account of morbidity and mortality increase, it is evident that searching for independent prognostic factors is needed. Aim of the Study. The aim of the study was to analyze routinely performed blood parameters as potential prognostic factors for kidney cancer. Material and Methods. We have retrospectively reviewed the records of 230 patients treated for renal cell carcinoma in the years 2000-2006. Preoperative blood parameters, postoperative histopathological results, and staging and grading were performed. To estimate the risk of tumor recurrence and cancer specific mortality (CSM) within five years of follow-up, uni- and multivariate Cox and regression analyses were used. To assess the quality of classifiers and to search for the optimal cut-off point, the ROC curve was used. Results. T stage of the tumor metastasis is the most important risk factor for early recurrence and cancer specific mortality (p < 0.001). The preoperative platelet count (PLT) above 351 × 103/uL (95.3%; 55.1%) and AUC of 77% are negative prognostic factors and correlate with increased cancer specific mortality (CSM) during the five-year follow-up (p < 0.001). Increased risk of local recurrence was observed for PLT above 243.5 × 103/ul (59%; 88%) and AUC of 80% (p = 0.001). The opposite was observed in the mean platelets volume (MPV) for cancer specific mortality (CSM). The cut-off point for the MPV was 10.1 fl (75.4%; 55.1%) and for the AUC is of 68.1% (p = 0.047). Conclusions. Many analyzed parameters in univariate regressions reached statistical significance and could be considered as potential prognostic factors for ccRCC. In multivariate analysis, only T stage, platelet count (PLT), and mean platelet volume (MPV) correlated with CSM or recurrent ccRCC.