Background: Acute Coronary Syndromes (ACS) represent a continuum of disease ranging from unstable angina, associated with reversible myocardial cell injury, to ST-segment elevation of myocardial infarction, associated with irreversible myocardial necrosis. Ischemia-Modified Albumin (IMA) as a sensitive biomarker of cardiac ischemia. IMA is a relatively new biomarker in the identification of myocardial ischemia in advance or in the absence of myocardial necrosis.Objective: This study was designed to assess sensitivity and specifity of “Ischemia Modified Albumin”, a new biochemical marker of early detection of myocardial injury in acute coronary syndromes.Methods: This study included 76 patients , who presented to the emergency department (ED) with acute chest pain within 3h of pain onset, between March and September 2013 , and 10 people (matched for age, gender and risk factors) as control group. The blood samples obtained from patients on admission and repeated 4-6 hours after admission to the coronary care unit (CCU) for those subsequently diagnosed with ACS by history, clinical examination, electro-cardiogram (ECG) and cardiac markers. IMA level was detected by Albumin-Cobalt Binding (ACB) test, and characteristic (ROC) curve was performed to detect the cut off value of IMA with best sensitivity, and the specificity in diagnosis of ACS. Results: There was a higher IMA level in paients with ACS (5.27 ±4) compared to control group (1.7 ± 0.8). The ROC curve showed that IMA level could be used to detect cases of myocardial injury in acute coronary syndromes at a level of 3.25u/ml, with 89.5% sensitivity and 100% specificity and 82% accuracy. On admission, there was a highly significant difference between IMA and troponin -I(Tn I) test regarding sensitivity in ST-elevation of myocardial infarction (STEMI=88.5 % vs.30.7%, p=0.001) and non ST-elevation of myocardial infarction (NSTEMI=94.4% vs. 16.7%,p=0.001 ) patients ,and also shown there was no significant difference between IMA on admision and cTnI at 4-6 hours after admission in STEMI ( 88.5% vs. 100%, p=0.633) and NSTEMI ( 94.4% vs. 100%, p= 0.829) patients ,and when comparing these changes in cTn I at 4-6 hours of admission to IMA results on admission revealed highly significant difference in favour of IMA in detecting myocardial ischemia in patients with unstable angina (UA=87.5% vs. 0%, p ˂ 0,001),but both (IMA and TnI)had 100% specificity. Conclusion: The IMA is highly sensitive for the early diagnosis of ACS in patients presenting to ED within 3 hours of pain onset, compared to other cardiac markers as Troponin I. IMA may be a useful biomarker for the identification of UA patients presenting with typical acute chest pain and/or abnormal electrocardiograms with negative Tn I.