Background: Cystatin C has been associated with Coronary artery disease (CAD) even within normal ranges of Estimated glomerular filtration rate (eGFR) suggesting existence of GFR independent cystatin C mediated cardiovascular disease (CVD) risk. This study aimed to assess the relation between the biomarker and CV diseases. Methods: This is Case Control study which was conducted on 88 cases at departments of Medical Biochemistry and cardiac cath lab, Faculty of Medicine, Zagazig. Subjects enrolled in the study were divides into 2 groups: Group (I) included patients with CAD while Group (II) included healthy people with normal coronary artery. Every patient had a complete medical history taken, a routine clinical examination, laboratory testing, electrocardiography, coronary angiography and cystatin C assessment. Results: Compared to the control group, the cases group's serum cystatin C median levels increased in a statistically significant way. A statistically significant positive connection was seen between the Gensini score and the levels of TC, LDL, serum Cys-C and a positive significant correlation between serum Cys-C levels and both LDL and fasting blood glucose. ROC curve analysis was done during our study to show the values of cystatin C as a possible biomarker in CHD at (cut off =0.769), which had a sensitivity of 81.8% and a specificity of 69.1%, predictive values for positive (PVP) and negative (PVN) are 72%, 79%, and 75%, respectively, of accuracy. Conclusion: We concluded that high level of cystatin C is considered as an additional risk factor of coronary artery disease.