Atherosclerosis with ensuing atherothrombosis is an inflammatory disease of the large arteries with high mortality and morbidity. Interactions between blood cells and the arterial vessel wall are considered to determine the progression of atherosclerotic plaques and the thrombotic complications. There is increasing evidence for important roles of activated platelets and platelet-derived microparticles in this disease process by contact with leukocytes, endothelial cells and smooth muscle cells. This paper gives an overview of newly described interactions of platelets and microparticles with other cells of the cardiovascular system via direct contact or via mediator release. The possible significance of these interactions is discussed within the context of vascular inflammation.