Background: Incidence of younger age Acute Myocardial Infarction (AMI) is increasing worldwide. This study was aimed to ascertain plasma PAI-1 as an independent biomarker in STEMI, Quantification and Establishing the indicative evidence range of Plasma PAI-1 and ascertaining it’s correlation with CK-MB in young south Indian ethnics. Methodology: This cross sectional study was conducted at MGMGH, Tiruchirapalli. Study subjects includes 40 Patients with typical chest pain, shows ST Elevation in ECG, rise in CK-MB and without any other risk factors of AMI. 40 age and sex matched control subjects were studied at the same time. Plasma PAI-1 (ELISA KIT-KOCH 3071) was assayed within six months of sample collection. Analysis of Serum Urea, Creatinine, Glucose, Lipid Profile, CK-MB and others risk factors of AMI was done on admission. Statistics was analyzed using SPSS -19.0. Results: There was a positive significance association observed in plasma PAI-1 (P ≤ 0.001), Serum Urea: P ≤ 0.001, Serum Glucose: P ≤ 0.04, Serum AST: P ≤ 0.001, Serum CK-MB: P ≤ 0. 001 and Serum HDL: P ≤ 0.008 between patients and control subjects. The Mean and SD of plasma PAI-1 for patients and Controls are 3450.76 ± 1406.68 and 1966.03 ± 1406.68. Furthermore an inverse association observed between plasma PAI-1 and HDL level. Conclusion: This study statistically confirmed the independent association between STEMI and plasma PAI-1 and established its analytical range as 3000-5000 pg/ml, wherein, it is 1000- 2000 pg/ml for controls also observed the inverse association of Plasma PAI-1 with serum HDL levels.