Acute Coronary Syndrome (ACS) is the most common disease and cause of mortality in both genders across the world and certain risk factors i.e. age, gender, smoking, diabetes, hypertension, drugs usage, weight etc are known to be associated with the disease. The aim of this study was to find if there is any correlation exists between ACS and hereditary genetic defect in endothelial nitric oxide synthase (ecNOS) gene as eNOS generates Nitric oxide in blood vessels and regulates the vascular tone hence directly affecting the cardiovascular function. Single nucleotide polymorphism (SNP) (Glu 298 Asp) in ecNOS was determined in 280 subjects, from Southern Punjab (in Pakistan) population, including (160 ACS patients and 120 healthy controls) by PCR-RFLP method and genotype was correlated with various risk factors as well as with serum cholesterol and triglyceride levels. Our results indicated that the genotype Glu 298 Asp was not associated with ACS but when various studied parameters were compared among patients suffering from various forms of ACS and their healthy controls, it was observed that age (45-55 years) (P = 0.05), gender (male) (P < 0.001), education (P<0.001), family history (P=0.03), hypertension (P<0.001), diabetes (P<0.01) and smoking habit (P = 0.03) were the significantly different parameters among them and may be associated with the incidence of cardiovascular disease. Cholesterol (161.5±79 mg/dL) level was found to be higher in patients (P = 0.04) than controls while triglyceride remained unaffected (P = 0.87) in both groups.