An organic light emitting display device includes pixels, a data driver, a scan driver, a control line driver and a temperature estimating unit. The pixels are respectively disposed at intersection portions of data lines, scan lines, sensing control lines and emission control lines. The data driver supplies data signals to the data lines. The scan driver progressively supplies a scan signal to the scan lines. The control line driver progressively supplies a sensing control signal to the sensing control lines during a temperature sensing period, and progressively supplies an emission control signal to the emission control lines during a normal driving period. The temperature estimating unit estimates temperatures of the pixels according to the amplitudes of currents supplied from the pixels through data lines during the temperature sensing period.