Background: Ischemic heart disease defined as stenosis or occlusion of coronary vessels by thrombi or emboli resulting from presence of risk factors as diabetes, obesity. Study design: Case control study. Subject: 76 patients will be selected from ICU patients from El kasr El Aini hospital presenting with acute coronary syndrome. Methodology: All patients will be subjected to full medical history, complete physical examination, serum pentrxin3 level, serum creatinine, serum highly sensitive CRP and serum Troponin I. Results: our results showing that sensitivity and specificity of pentraxin3 for the diagnosis of acute coronary syndrome appear to be higher than those of troponin. Conclusion: From previous results we can conclude that pentraxin3 is a strong independent biomarker for acute coronary syndrome. The present study clearly demonstrate that the diagnostic sensitivity and specificity of pentraxin3 in acute coronary syndrome in early stage appear to be superior to these hs CRP and troponin , thus indicating that pentraxin3 is one of the useful biomarker for detecting acute coronary syndrome alone or in combination with other biomarker