A ratchet wrench includes a box, a button, a switch and an engagement element. The box includes an upper opening, a channel, a switch chamber in communication with the upper opening via the channel, and a button aperture in communication with the switch chamber. The button is inserted in the switch chamber via the button aperture. The button includes an abutment portion to keep the button in the box. The switch includes an arched portion extending in the switch chamber around the button. The switch is operable to rotate the button by the abutment portion without hindering movement of the button into and from the button aperture of the box. The engagement element is inserted in the channel of the box. The abutment portion is operable to move the engagement element in the channel to extend a front edge from the upper opening of the box.