Cell activation or apoptosis leads to plasma membrane blebbing and microparticles (MPs) release. MPs are submicron membrane vesicles expressing a panel of oxidized phospholipids and proteins specific of the cells they originate from. Exposure of negatively charged phospholipids and tissue factor confers a procoagulant potential to MPs. Increases in plasma MPs levels, particularly those of endothelial origin, reflects cellular injury and appears now as a surrogate marker of vascular dysfunction. MPs are also biologically active and stimulate pro-inflammatory responses in target cells. Thus, MPs can promote a prothrombogenic and pro-inflammatory vicious circle leading to vascular dysfunction. A better understanding of MPs composition, as well as their effects and the mechanisms leading to their clearance will likely open new therapeutic approaches in the treatment and the prognosis of cardiovascular diseases.