Abstract. Atherosclerosis is a state in which plaque (fat, cholesterol, and other substances) builds up inside the arteries that leads to carotid artery stenosis: a narrowing in the large arteries located on either side of the neck that carry blood to the face, head and brain. Carotid stenosis is often associated with permanent injury of a part of the brain (strokes) due to loss of its blood supply i.e. ischemia and mostly results in severe disability or death. Hematocrit or packed cell volume is the volume of red blood corpuscles in relation to that of whole blood. The purpose of our research is to perform a Computational Fluid Dynamics (CFD) study of blood flow with the percentage changes of hematocrit to analyze the hemodynamic and physiological behavior of atherosclerosis. Our constructed 2D geometry model has been analyzed using Finite Element method for different stages of atherosclerosis. Here our focus was on the behavior of the wall shear stress, velocity gradient, and pressure gradient. These parameters were analyzed for different percentages of hematocrit and different stages of atherosclerosis. The analysis presented conclusive difference in these parameters which can be used to identify the atherosclerosis formation.