Cardiac troponin T and I (cTnT, cTnI) are sensitive biochemical markers of myocardial cell necrosis and have been adopted as the gold standard tests for acute myocardial infarction. Subtle elevations in cTn above the detection limits of the currently available commercial assays confers poor prognosis. These markers are superior to classical enzyme markers of necrosis due to their cardiospecificity. The diagnosis of drug-induced cardiac toxicity using the classical enzymes is problematic due to the high elevations of these markers in skeletal muscle necrosis. cTnT and cTnI are now being adopted as sensitive biomarkers of drug-induced cardiac toxicity.