Ischemic coronary syndrome is still the most frequent cause of mortality in the United States. Despite extensive investigation into the diagnosis of acute myocardial infarction (MI), this process remains quite complex because the majority of patients with chest pain have atypical symptoms and nonspecific electrocardiogram (ECG) changes and fall in the low or medium risk category. The biochemical cardiac markers play an important role in helping physicians make the diagnosis of acute MI and stratify patients for risk modifications. The use of cardiac markers in the diagnosis of acute MI is discussed extensively on pages 36-44 of this issue. This article focuses on reviewing other clinical applications. This field is large and rapidly expanding, making it impossible to cover every single clinical application of cardiac markers. Several research efforts are underway to find better cardiac markers and develop new applications for them. We review the literature on the use of cardiac markers, particularly troponin, with the risk stratification of acute coronary syndromes, the detection of reperfusion, perioperative MI, periprocedural MI, myocarditis, cardiac contusion, and MI associated with sepsis.