Studies on platelet function have accelerated and gained popularity since the advent of novel treatment modalities and techniques on atherosclerotic vascular disease, such as antiplatelet drugs and stents. Today it is widely known that platelets exert a fundamental role in inflammation in addition to their long known role in homeostasis and thrombotic events. Interaction with endothelial cells and leukocytes mediates inflammation, contributes to atherogenesis and modulates immune activity. Platelet activation which is a central factor in many arterial disorders may be triggered by multiple pathways. Platelet activation is shown as forming a larger shape, aggregation and releasing various active contents. Mean platelet volume is a marker of platelet size, function and activation. Increased mean platelet volume is shown by active and large platelets that release more thromboxane A2 than smaller ones. The aim of this review is to determine whether early detection of platelet activation via increased mean platelet volume would help to recognize the pro-inflammatory state and administer appropriate and effective treatment properly. An easily detectable marker by using a prompt and functional technique would help our approach to inflammation caused by platelets.