Background/aimC-reactive protein (CRP) to albumin ratio (CAR) is predictive marker of systemic inflammatory state in atherosclerotic coronary diseases when compared to predictive value of these two markers separately. We aimed to evaluate the relationship between CAR and the coronary artery calcium (CAC) score, Coronary Artery Disease-Reporting and Data System (CAD-RADS) score in patients’ unknown diagnosis of coronary artery disease (CAD) underwent coronary CTA (Computed Tomography Angiography) and were classified by CAD-RADS scores. Materials and methods A total of 187 patients consecutively referred for the evaluation of their chest pain underwent coronary CTA were included retrospectively. Results CRP, CAR, and CAD-RADS scores were higher in patients with CAC score > 400 than the other groups (p < 0.001). We found positive correlation between CAR and CAC score (r= 0.384, p < 0.001), and also there was a positive correlation between CAR and CAD-RADS score (r= 0.462, p < 0.001). Multivariate logistic regression analyses showed that low density lipoprotein cholesterol (LDL-C), CAD-RADS score, and CAR were independent predictors of CAC score (p < 0.05). Conclusion Higher CAR can be a predictive marker of atherosclerosis and CAD. CAR may be useful in the management of patients before invasive coronary angiography. Further studies are needed to clarify the pathophysiologic role of CAR in patients with atherosclerotic coronary heart diease.