An elliptical exercise apparatus includes a frame unit having a base frame, two crank arms, and two link units disposed respectively on left and right sides of the frame unit and each including a pedal rod connected pivotally to one of the crank arms. An adjustment unit includes a motor mounted on the frame unit, a threaded rod connected drivenly to the motor, a pull unit connected pivotally to the frame unit and connected drivenly to the threaded rod, and two roller sets connected pivotally to and disposed respectively on left and right sides of the pull unit. Each roller set is disposed in rolling contact with the pedal rod of a respective link unit. The roller sets are limitedly movable toward or away from an axis of rotation of the crank arms by a pulling action of the pull unit.