Background: COPD represents an important public health challenge and is a major cause of chronic morbidity and mortality throughout the world, where COPD are associated with an increase in airway and systemic inflammation. Aim of this study: the aim of this study was to assess the role of MPV as a marker of inflammation in COPD patients and to evaluate its role as a prognosis parameter in AE COPD. Patients and Methods: This study was carried at Chest Department of Zagazig University Hospitals, during the period from April 2017 till October 2017, the study included 25 stable and 25 exacerbated chronic obstructive pulmonary disease (COPD) patients, selected in non randomized manner. Results: showed that there was no significant statistical difference in RBCs, hemoglobin and hematocrit content and a highly statistical significant increase in white blood cells (WBCs) count, neutrophils count, while lymphocytes shows significant statistical increase among the studied groups. The results showed that the Validity of MPV cutoff value, Sensitivity was 76.0%, Specificity was 80.0%, +VE predictive was 79.1%, -VE predictive was 76.9% and the accuracy was 78.0%.Conclusion: MPV is an easily accessible low cost marker of inflammation in AECOPD. Decreased MPV values may be used as indicator for negative acute-phase reaction in the exacerbated COPD patients. Cut off-point of MPV