Background: Â Acute Myocardial Infarction (AMI) is an emergency medical condition which still has high mortality and morbidity. In recent decades, its prevalence has a tendency to increase, parallel with other chronic diseases. One of suspected contributing factor in AMI is the presence of C1562T polymorphism on MMP-9 gene which increases plasma MMP-9 concentration and destabilizes the plaque. However, this notion needs further confirmatory studies, as there are several contradictive reports regarding their association. This Study aimed to determine the relationship between C1562T polymorphism with the increase of MMP-9 concentration in AMI. Method: A cross-sectional was conducted in Cardiovascular Centre of Sanglah General Hospital. The peripheral blood samples were obtained from subjects, and the DNA and blood plasma was isolated. The polymorphism was detected using PCR and RFLP while MMP-9 concentration was determined by ELISA. Results: The average concentration of plasma MMP-9 was found to be at 8.33 ng/mL which ranged from 0.74 ng/mL until 31.93ng/mL. The proportion of MMP-9 C1562T polymorphism was 20% of all subjects. The average concentration of MMP-9 was higher than cut-off standard which is 0.6 ng/mL. Analysis within the group revealed that CT-genotype had significantly higher average MMP-9 compared with CC phenotype (11.27 ng/mL vs. 7.65 ng/mL). Conclusion: C1562T polymorphism appears to be significantly associated with AMI by increasing the concentration of MMP-9 in blood plasma.