The role of nanotechnology in cardiovascular diagnosis is expanding rapidly. The goal of this brief review is to illustrate selected examples of nanosystems that have been applied to the arenas of atherosclerosis, thrombosis, and vascular biology. The technologies for producing targeted nanosystems are multifarious and reflect end uses in many cases. The results to date indicate rapid growth of interest and capability in the field. The future of cardiovascular diagnosis already is being impacted by nanosystems that can both diagnose pathology and treat it with targeted delivery systems.