An organic light emitting display device is configured to compensate for deterioration of organic light emitting diodes (OLEDs) included in the device. The organic light emitting display device includes: a plurality of pixels; a timing controller for generating a comparison signal to determine a deterioration degree of an OLED included in each of the pixels; a sensing unit for sensing a deterioration information of the OLED; a supply time controller coupled between data lines and a data driver; a compensation unit for controlling the supply time controller so that a supply time of a data signal varies to correspond to the deterioration information and the comparison signal; and a switching unit coupled to the data lines, the sensing unit, and the supply time controller. The switching unit is configured to selectively couple the data lines to the sensing unit or the supply time controller.