Two infonnal meetings of consultants expert in hemostatic phenomena and in atherogenesis were held in Bethesda, Maryland, in December 1975 and February 1976 by the National Heart, Lung, and Blood Institute. Their purpose was to discuss the current status of knowledge concerning the thrombotic process in the pathogenesis of atherosclerosis. It was readily agreed that thrombosis often played a major role in plaque building and in plaque complication. It was also commented, however, that the data were qualitative in nature and that quantitative infonnation was remarkably sparse. The term thromboatherogenesis was thought to be appropriate for those phenomena in which the full expression of the thrombotic process is manifest. At the same time, recent research was noted in which what appears to be an important pathway for the initiation of atherogenesis arises from the reaction of platelets with injured arterial endothelium and'Subendothelium without necessarily involving the complete classical thrombotic process. A name was not coined for this circumstance, but it was held that thromboatherogenesis was not a fully appropriate one.