Background: Recent studies have revealed a prognostic impact of the MPV (mean platelet volume)/platelet count ratio in terms of survival in advanced non-small cell lung cancer. However, there has been no direct analysis of the survival impact of MPV in patients with mCRC. The aim of the study is to evaluate the pretreatment MPV of patients with metastatic and non-metastatic colorectal cancer (non-mCRC) and also the prognostic significance of pretreatment MPV to progression in mCRC patients treated with bevacizumab-combined chemotherapy. Materials and Methods: Fifty-three metastatic and ninety-five non-metastatic colorectal cancer patients were included into the study. Data on sex, age, lymph node status, MPV, platelet and platecrit (PCT) levels were obtained retrospectively from the patient medical records. Results: The MPV was significantly higher in the patients with mCRC compared to those with non-mCRC ($7.895{pm}1.060$ versus $7.322{pm}1.136$, p=0.013). The benefit of bevacizumab on PFS was significantly greater among the patients with low MPV than those with high MPV. The hazard ratio (HR) of disease progression was 0.41 (95%CI, 0.174-0.986; p=0.04). In conclusion, despite the retrospective design and small sample size, MPV can be considered a prognostic factor for mCRC patients treated with bevacizumab-combined chemotherapy.