Microparticles (MPs) are small membrane vesicles that are released from many different cell types by exocytotic budding of the plasma membrane in response to cellular activation or apoptosis. MPs may be involved in both physiological processes and clinical treatments because they express phospholipids, which function as procoagulants. Elevated levels of platelet-derived MPs, endothelial cell-derived MPs, and monocyte-derived MPs are observed in almost all thrombotic diseases occurring in venous and arterial beds. Several studies have shown that the quantity, cellular origin, and composition of circulating MPs depend on the type of disease, the disease state, and medical treatment. Although MPs were initially thought to be small particles with only procoagulant activity, they are now known to have many different functions. An increasing number of studies have identified new implications of elevated MPs in clinical disorders. On the basis of evidence available till date, the present review suggests that MPs may be a useful biomarker in identifying atherothrombosis.