Introduction. Acute coronary syndrome (ACS), encompassing unstable angina, non-ST-segment eleva­tion myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI), is a major global health concern due to its high morbidity and mortality. Research highlights a link between ACS and elevated acute phase reactants like C-reactive protein, emphasizing the role of inflammation and atherosclerosis. Serum fibrinogen, crucial in thrombus formation and an inflammatory marker, is significant in the coagu­lation process. This study investigates the predictive value of serum fibrinogen levels and the GRACE score for 3-month mortality in ACS patients. Aim. To examine the clinical profile of ACS patients and evaluate serum fibrinogen and GRACE score as prognostic markers for 3-month mortality. Methodology. A prospective observational study was conducted on 50 patients diagnosed with ACS at Saveetha Medical College Hospital. The study included adults over 18 with ACS, excluding those with severe comorbid conditions like end-stage liver disease or malignancy. Serum fibrinogen levels were measured at presentation and at 3 months using an automated coagulation analyzer. GRACE scores were calculated, and clinical assessments including ECG, cardiac markers, and ECHO were conducted. Data analysis involved IBM SPSS Statistics, utilizing descriptive statistics, t-tests, ANOVA, and Pearson's Correlation. Results. The study group had diverse demographics and a high prevalence of cardiovascular symptoms and comorbidities. The clinical profile of ACS showed a higher incidence of STEMI. Serum fibrinogen levels varied significantly across different Killip classes at presentation and at 3 months, with the highest levels in the more severe classes. Higher serum fibrinogen was linked to recurrent heart failure admissions and higher KILIPS class. However, there was no significant difference in fibrinogen levels between patients with and without interventions. The GRACE score was higher in STEMI patients, those with LV dysfunction, and correlated with higher serum fibrinogen. Lower FACIT F scores, indicating higher fatigue, were associated with higher fibrinogen levels and readmissions for heart failure. Conclusion. Higher serum fibrinogen levels and GRACE scores at presentation and at three months are indicators of severe myocardial infarction, increased heart failure readmission rates, and greater fatigue in ACS patients. These markers are valuable for evaluating morbidity in ACS and can aid in enhancing patient management strategies.