• Many diseases in children are associated with thrombotic tendencies either as a complication or as part of the patho-physiologic process. Disorders in which platelet consumption and/or activation occur incude myeloproliferative syndromes, sickle cell disease, cardiac prostheses, arteriovenous shunts, vasculitis, diabetes mellitus, and hemolytic-uremic syndrome and other renal diseases. Platelet involvement can be demonstrated by several indicators, including an increase in platelet release product levels in the plasma (β-thromboglobulin, platelet factor 4, and thromboxane B2). The agents that have the greatest success in thrombotic disorders where platelet involvement is prominent include the prostaglandin pathway cyclo-oxygenase inhibitors aspirin and sulfinpyrazone, as well as dipyridamole. Although indications and dosages for the use of antiplatelet agents in children can be suggested, the treatment of each patient should be individualized in light of current knowledge.