Objective: The prognostic value of red cell distribution width to platelet count ratio (RPR) in patients with breast cancer is not clear. This study aims to evaluate the prognostic significance of red cell distribution width to platelet count ratio in breast cancer patients. Material and Methods: A retrospective analysis was performed on 150 patients with non-metastatic breast cancer between January 2014-December 2018. The optimal cut off value of RPR was 0.54 for diseasefree survival (DFS). The chi-square test or Fisher’s exact test was used to evaluate relationships between the RPR and other clinicopathological variables. Kaplan-Meier log-rank test was used to determine the effect of variables on DFS. Cox’s proportional hazards model was used for multivariate analysis. Results: Median follow-up period was 39±1.174 (13-66) months and 5-year survival was 96.60%. There was no relationships between the RPR and clinicopathological variables. Kaplan-Meier analysis showed significant correlation between elevated RPR level (p=0.001) and high MPV(mean platelet volume)/Platelet(P) ratio (p=0.006) and DFS. DFS was found to be short in patients with high RPR and high MPV/P ratio. When multivariate analysis was performed with cox regression analysis, RPR level (p=0.025) and tumor size (p=0.047) were found to be independent prognostic factors . RPR was found to be a more valuable prognostic marker than mean platelet volume to platelet ratio (MPV/P). Conclusion: We found that high RPR levels before adjuvant treatment were associated with poor DFS in patients with curative resected breast cancer. Accordingly, the RPR level can be used as a prognostic marker in non-metastatic breast cancer. However, further studies conducted with a larger number of patients are needed.