Purpose: Cardiac troponin is specific to the myocardium and is a useful biomarker for the diagnosis of myocardial infarction. Detection of elevated blood levels of troponin indicates damage to myocardial cells, but does not indicate the mechanism. Causes other than acute coronary syndromes and myocardial infarction can result in troponin elevation and these conditions frequently occur in critically ill patients in the intensive care unit. The interpretation, clinical significance and appropriate management of an elevated troponin measurement in critically ill patients are uncertain. Source: Studies evaluating the prevalence of troponin elevation among medical-surgical intensive care unit patients, and its prognostic significance with regards to adverse outcomes will be reviewed. Conclusions: Cardiac troponin elevation is common and observed in 40 to 50% of critically ill medical and surgical patients. Elevated levels appear to identify patients at increased risk for death in the intensive care unit or hospital setting. This finding, and its relation to myocardial infarction and acute coronary syndromes, requires prospective study to better understand the implications for diagnosis and management.