Purpose: Acute coronary syndrome (ACS) is a life-threatening cardiac disease identified by acute, regional reductions in coronary blood flow, resulting in myocardial ischemia, or infarction, and manifesting as discomfort in the chest area, neck, or arms. Frequently, ACS is provoked by an atherosclerotic plaque; therefore, coronary atherosclerosis is converted into a chronic disease to an acute medical emergency. The purpose of this study was to explore the differences among these variables in patients less than 45 years of age suffering from this major health problem compared to older adults admitted with an ACS diagnosis, and to adopt an optimized temporary management. Patients and Methods: A retrospective chart review study was conducted on a total of 652 ACS patients admitted at King Fahad Hospital of the University (KFHU) between 2015 and 2020. The patients' medical records were utilized for obtaining demographic data, presenting symptoms, risk factors, and clinical outcomes. Results: Overall, 652 patients were enrolled. Of these, 109 patients (16.7%) were under 45, with a mean age of 38 ± 7. Younger patients showed a higher rate of palpitation (23.9% versus. 13.6%; P = 0.019). A positive smoking history and a family history of CAD were seen more often in younger patients (42.2% vs 27.3%, P < 0.001; 22.9% vs 9.4%, P < 0.001, respectively). Older patients had greater renal impairment with higher creatinine (median = 1.10 mg/dl (range, 0.3-13.0) vs 1.0 (0.3-19.0; p = 0. 001), BUN (median = 16.0 (mange, 0.9-141.0) vs 12.0 (0.9-49.0); P < 0.001)). Younger patients had higher levels of LDL and total cholesterol (median 138c. 115; p < 0.001) and cholesterol (median 209 vs 178.5; p < 0.001). Hospital mortality was 0.9% in younger patients versus 7.4% in older patients (P = 0.004). Conclusion: Palpitations, smoking, family history, higher LDL levels, and total cholesterol levels were more prevalent in adults younger than 45 years old with ACS. Impaired renal function, hypertension, and diabetes were more in older patients with ACS.