Despite advances in diagnosis and management, ischemic heart disease remains the leading cause of death in the USA. Serum cardiac enzymes, one of the three fundamental criteria for establishing the diagnosis of myocardial infarction, are not specific for cardiac muscle and have a narrow time-window. The recent development of monoclonal antibodies to cardiac troponin I and troponin T has resulted in cardiac-specific assays. Several published studies have documented the utility of troponin proteins in the evaluation of myocardial necrosis. A brief overview of the characteristics and clinical utility of troponin T and I is presented here.