Millions of patients present annually with chest pain, but only 10% to 15% have myocardial infarction. Lack of diagnostic sensitivity and specificity of clinical and conventional markers prevents or delays treatment and leads to unnecessary costly admissions. Comparative data are lacking on the new markers, yet using all of them is inappropriate and expensive. The older markers like aspartate amino-transferase, creatine kinase, lactate dehydrogenase etc. lost their utility due to lack of specificity and limited sensitivities. Cardiac troponin levels but negative CK-MB who were formerly diagnosed with unstable angina or minor myocardial injury is now reclassified as non–ST-segment elevation MI (NSTEMI) even in the absence of diagnostic ECG changes. CK-MB is both a sensitive and specific marker for myocardial infarction. Cardiac troponin T is a cardio-specific, highly sensitive marker for myocardial damage. Cardiac troponin I is a contractile protein exclusively present in the cardiac muscle. The absolute cardiospecificity of cTnI allows the diagnosis of myocardial infarction distinct from muscle lesions and non-cardiac surgery.