Background : In early phase of acute chest pain, diagnosis of coronary artery disease(CAD) is often difficult in emergency department (ED) due to less sensitive ECG and delayed cardiac necrosis markers. Ischemia modified albumin (IMA) has recently been reported to be an early sensitive biochemical marker of ischemia. Objectives : The aim of this study was to evaluate the diagnostic value of IMA in patients with suspected CAD and less sensitive EKG/delayed cardiac necrosis markers. Subjects and Method: We enrolled consecutive 80 patients(mean age:54 years , male: 55) presenting to the ED due to suspected CAD with chest pain in 6 hours of chest pain. ECG check and blood sampling for IMA and cardiac troponin-T were done within 1 hour at ED. The diagnosis of CAD was based upon clinical findings, results of serial ECG/troponin-T and coronary angiography. The ideal cutoff value of IMA for CAD was calculated by Receiver Operator Characteristic (ROC) curve analysis. Results: The CAD including acute coronary syndrome was diagnosed in 38/80(48%). The optimum diagnostic cutoff point for IMA levels in this study population was found to be 99.5 U/mL by ROC analysis. The ROC curve area for the IMA test was 0.80 (95% confidence interval, 0.69-0.90, p<0.001). IMA levels>99.5 U/mL demonstrated a sensitivity of 76%, specificity of 81%, positive predictive value of 78% and negative predictive value of 79% for the diagnosis of CAD. Conclusions: IMA might be a useful ischemic marker of CAD in patients presenting within 6 hours after symptoms of chest pain.