An organic light emitting display device that prevents distortion of the image by preventing the transmitting light from scattering, and by preventing the degradation of the brightness and color coordinates caused by external light transmitting through the organic light emitting display device. The device includes a transmitting region and separate pixel regions interposed within the transmitting region; thin film transistors, a passivation film covering each thin film transistor; a pixel electrode that is electrically connected to the corresponding thin film transistor; an opposite electrode that faces the pixel electrode and is able to transmit light; an organic light emission layer that is interposed between the pixel electrode and the opposite electrode; a first electrode formed on a second surface of the substrate; a second electrode facing the first electrode; and a light transmission adjusting layer disposed between the first electrode and the second electrode.