An electric power steering apparatus is configured to provide steering assistance as rotary torque of a driving toothed-pulley fixedly fitted to a rotary shaft of an electric motor is transmitted through a toothed belt to a driven toothed-pulley that rotates together with a ball screw nut in an integrated manner. The electric power steering apparatus is configured such that the amount of axial travel of a rack shaft is limited when a rack end and a housing come into contact with each other in the axial direction. The electric power steering apparatus includes a tilt allowing portion configured to cause the ball screw nut to tilt relative to a ball screw shaft such that the distance between the center of rotation of the driven toothed-pulley and that of the driving toothed-pulley increases when the rack end and the housing come into contact with each other in the axial direction.