Background: Among the non-communicable illnesses in the world ,Coronary artery disease (CAD) is one of the most common and it remains a major cause of morbidity and mortality, with acute coronary syndromes (ACS) being the most severe. Acute coronary syndrome (ACS) is defined by an abrupt reduction in the flow of blood to the heart. It is frequently brought on by non-atherosclerotic or thromboembolic coronary etiologies, leading to ST segment elevation myocardial infarction (STEMI), nonSTEMI (NSTEMI), and unstable angina (UA). An estimated 7 million individuals globally receive an ACS diagnosis each year. Objective: To investigate the relationship between diastolic blood pressure at admission and subsequent cardiovascular mortality in patients with acute coronary syndrome. Materials and methods: This prospective cohort study was conducted in the Medicine Department ,Guru Nanak Dev Hospital, Amritsar. A total of 50 patients of Acute Coronary Syndrome were enrolled in this study.Their Diastolic Blood Pressure (DBP) was measured at the time of admission and were followed up for subsequent one month cardiovascular mortality. Results: Our study observed that lower DBP at admission is associated with a higher risk of mortality, suggesting that patients presenting with lower DBP require more immediate and intensive care.The mean DBP for those who experienced mortality was 55 mmHg, with a standard deviation of 19.30. In contrast, the mean DBP for survivors was significantly higher at 78.29 mmHg, with a standard deviation of 18.30. The p-value for this difference is <0.0001, indicating a highly significant statistical difference between the two groups. The Pearson’s correlation coefficient (R) is -0.6237, showing a moderate negative correlation between DBP at admission and mortality. This signifies that as DBP at admission increases, the likelihood of mortality decreases, and vice versa. Conclusion: In conclusion, this study provides a comprehensive analysis of the clinical characteristics, treatment modalities, and outcomes of a sample of 50 patients diagnosed with myocardial infarction, with a predominance of STEMI cases. Significant differences in diastolic blood pressure (DBP) at admission between survivors and non-survivors were observed, with lower DBP associated with higher mortality, underscoring the importance of early and accurate blood pressure management in these patients.