A 2D/3D image display device including a display unit with a plurality of gate lines, a plurality of data lines, and a plurality of pixels, the plurality of gate lines crossing the plurality of data lines, and the plurality of pixels being coupled to the plurality of gate lines and the plurality of data lines; and a controller for receiving an input signal and setting a first driving frequency or a second driving frequency according to the input signal. An image of one frame operating according to the second driving frequency receives and displays the same image data for each of a first period and a second period, a video signal transmitted to one of the plurality of pixels for the first period has first polarity, and a video signal transmitted to one of the plurality of pixels for the second period has second polarity.