Introduction:Acute myocardial infarction is common causes of death worldwide specially in advancing age.It is uncommon disease in young individual and its incidence varies between 2% and 10%. Lifestyle and dietary changes have lead to obesity, increase level of blood pressure, glucose and cholesterol in younger adults. As a result, these individuals are prone to increased atherothrombotic state. Methodology:A descriptive observational study was conducted from September 2015 to December 2016 after approval from institutional ethics committee and written informed consent from patients at SDMH, Jaipur. 92 patients with ST segment elevated MI were included in the study. Socio demographic, clinical, investigation & treatment information were collected. Data obtained were compiled & analyzed using Microsoft Excel and Primer software. Results:Out of 92 cases, 79 (85.9%) were male and 13 (14.1%) were female. 34 (37%) cases were in young age group (<45 yrs) and 58(63%) cases were in older age group (>45 yrs). Significant difference is observed in mean thrombus load in young age group (3.79±1.23) and older age group (2.86±1.47). Mean thrombus load was significantly more in young age group in male (3.80±1.22) as compared to older (2.91±1.41) andalso in female (3.67±1.52) as compared to older (2.60±1.77). Conclusion: The most common pathophysiology associated with ST elevated myocardial infarction was thrombus. Factors like male, young age, smoking, dyslipidemia, diabetes mellitus, and hypertensionhad high thrombus load.