Cardiovascular diseases are the main cause of death in the world. Next to efforts to reduce thecardiovascular risk factors, several drugs are resorted to decrease morbimortality associated to thesediseases: antihypertensive, antidiabetic, hypolipemiant and platelet antiaggregant drugs are used amongothers.Due to the participation of platelets, not only in the early stages of the atherogenesis but also in theartery thromboses, the use of platelet antiaggregant drugs is very relevant in the primary and secondaryprevention of the artery thrombosis.In this review, after a brief description of the primary hemostasis, aspects of antiplatelet like mechanismsof action and use asocied risks during the last 10 years are adressed. Primarily literature source was www.pubmed.com. The terms used in the search were: platelet antiaggregant, aspirin, dipyridamole,clopidogrel, abciximab, among others, then we searched the full texts of articles of interest and also usedsome hematology books.