Pulsatile flow of blood through a catheterized artery in the presence of a mild stenosis is investigated in this paper. Blood has been represented by a Newtonian fluid. By employing a perturbation analysis, analytic expressions for the velocity profile, flow rate, wall shear stress and longitudinal impedance, are derived. The influence of stenosis height and radius of catheter on axial velocity, wall shear stress and longitudinal impedance are represented graphically and discussed. Graphical results show that wall shear stress and resistance to flow increase while axial velocity decreases with height of the stenosis as well as radius of catheter.