Acute coronary syndrome (ACS) is one of the leading causes of mortality and morbidity worldwide. Atherosclerosis with plaque disruption and superimposed thrombosis is the common underlying cause. Coronary artery occlusion leads to clinical manifestations of unstable angina (UA) or acute myocardial infarction (AMI)[1].Platelet activation and aggregation have long been noted in the pathophysiology of coronary heart disease because platelets play an important role in contributing to thrombus formation after coronary plaque rupture. Mean Platelet Volume (MPV) is a simple and reliable thrombocyte size index, which correlates with platelet functional status, as a marker of the risk of atherothrombosis. In patients with non–ST elevation ACS, it has been shown that higher MPV indicates not only an increased risk of non-STEMI, but also ischemic complications. [2]. However, the association between MPV and the risk of acute coronary events, to the best of our knowledge, is under investigated. Hence present was carried out to find the mean platelet volume in patients with acute coronary syndrome. Aim:The aim of this study is to investigate whether there is an association between mean platelet volume (MPV) measurement and cardiac Troponin I (cardiac Troponin I) in patients admitted with a suspected diagnosis of ACS and to assess the potential diagnostic efficiency of MPV in the diagnostic workup for ACS Material and methods::The study was conducted at KRISHNA INSTITIUE OF MEDICAL SCIENCES ON 96 patients who inclusive fulfill the criteria’s were chosen as study subjects.Patients who are admitted in Medical Intensive Care Unit at Krishna hospital were included in the study. The main objective of this study was to study the association between mean platelet volume and acute coronary syndrome. At the time of registration, the baseline information was taken especially with respect to sociodemographic factors, clinical findings, and other investigations. Thus, each and every patient was followed up in till discharge. The data thus collected was analyzed to find role mean platelet volume in patients with acute coronary syndrome: a supportive diagnostic predictor. The collected data was compiled in Microsoft Excel 2010. Data describing quantitative measures was expressed as mean, median, mean + SD, standard deviation. Qualitative type of data was expressed as percentage or proportion. Data was analyzed using SPSS (Statistical Package for Social Sciences) software 21 version, OpenEpi Software Version 2.3. For quantitative type of data test of significance applied was student t test and for Qualitative data Chi square test was applied. Results: A total 96 patients were enrolled in this observational, comparative study, of them 48 patients were with Acute coronary syndrome (group I) and 48 were without Acute coronary syndrome (Group II). Conclusion: This study concludes that there was significant association between mean platelet volume (MPV) and presence of Acute coronary syndrome. Mean platelet volume being simple, cost-effective tool that can be done along with biochemical cardiac markers to predict an impending adverse event in Atherosclerotic cardiovascular disease [ASCVD]. We suggest that along with ECG and other biochemical parameter of ACS [CPKMB,TROPI], mean platelet volume can be supportive diagnostic parameter in diagnosis of Acute coronary syndrome.