An organic electroluminescent display device, includes: a gray level extractor that extracts gray levels of frame data signals for a frame image; an image type determiner that determines a type of the frame image using a distribution of the gray levels of the frame data signals, the type of the frame image being one of a low-gray-level type, a medium-gray-level type and a high-gray-level type; a gamma reference voltage generator that selects a set of gamma reference voltages based upon the image type; a data driver converting the frame data signals into frame data voltages using the selected set of gamma reference voltages; a timing controller that supplies the frame data signals to the data driver; and a display area including pixels having an organic light emitting diode that display the frame image.