Background: Acute coronary syndrome (ACS) refers to a spectrum of symptoms compatible with acute myocardial ischemia. Worldwide acute coronary syndrome (ACS) is one of the main reasons for hospital admission and the leading cause of death. Several risk factors have been identified. However high blood pressure and hypercholesterolemia remain the most important risk factors in (ACS). Objective: To determine the risk factors associated with ACS among patients admitted to the coronary care unit (CCU) in the Military Hospital-Sana’a. Methodology: Study design according to a case-control study. Two groups of patients were included in this study, the first group was cases who have (ACS), and the second group was control cases admitted to CCU for other causes. All data were recorded in a special sheet including demographic, clinical presentation, investigation, and treatment plan. The data was entered into PC and analyzed statistically. Results: There were 124 patients with ACS versus 91 control patients without ACS. The majority of participants in the two groups were males (80 %). Their age ranged from 18 to 95 years old with a mean age of 53.9 ±13.6 years. (86.5 %) of them were 40 years old or above. The significant risk factors associated with ACS were hypertension, Khat chewing found in 71.6 %, 64.4%, of the patients, respectively. Another significant risk factor was dyslipidemia which was higher among ACS patients than the control group with a P-value of < 0.05. Conclusion: Preventing the program from avoiding risk factors that were associated with ACS may decrease the occurring of ACS and reduce the morbidity and mortality in Yemeni patients.