A dual panel-type organic electroluminescent display device includes first and second substrates facing and spaced apart from each other, an array element layer disposed along an inner surface of the first substrate, the array element including a thin film transistor, a connection pattern disposed on the array element layer and electrically connected to the thin film transistor, a color filter layer disposed along an inner surface of the second substrate, the color filter layer including red, green, and blue color filters, an overcoat layer disposed on the color filter layer, the overcoat layer including a hygroscopic material, an organic electroluminescent diode disposed on the overcoat layer and connected to the connection pattern, the organic electroluminescent diode including a first electrode, an organic light-emitting layer, and a second electrode sequentially formed on the overcoat layer, and the organic light-emitting layer emits substantially monochromatic light, and a seal pattern along peripheral portions between the first and second substrates.