The aim of this work is to introduce a methodology to study the stent expansion and the subsequent deformation of the arterial wall towards the outside direction in order arterial lesion to be rehabilitated and blood flow to be restored. More specifically, a coronary artery and the plaque are reconstructed using intravascular ultrasound and biplane angiography. The finite element method is used for the modeling of the interaction between the stent, balloon, arterial wall and plaque. Appropriate material properties and boundary conditions are applied in order to represent the realistic behavior of each component. We observe that stresses are increased at the region of the first contact between the stent and the wall, which may be considered crucial for plaque rupture. Furthermore, the average calculated stress on the plaque is higher than the average stress on the arterial wall. Thus, stent positioning and deployment depends on a considerable degree on the plaque properties rather than the general arterial geometry. Results indicate that numerical modeling can provide a prediction of the arterial behavior during stent implantation.