An organic electroluminescent device includes first and second substrates spaced apart from and attached to each other, the first and second substrates including a plurality of pixel regions and a periphery region surrounding the plurality of pixel regions, a plurality of gate lines on an inner surface of the first substrate, a plurality of data lines crossing the plurality of gate lines, a plurality of driving thin film transistors, each of the driving thin film transistors adjacent to one of the plurality of pixel regions, a plurality of power lines connected to the driving thin film transistors, a plurality of gate pads connected to an end portion of the gate lines within the periphery region, a plurality of data pads connected to an end portion of the data lines within the periphery region, a plurality of power pads connected to an end portion of the power lines within the periphery region, at least one dummy pad within the periphery region, the at least one dummy pad being independent of each of the gate pads, the data pads, and the power pads, a first electrode on an inner surface of the second substrate, the first electrode connected to the dummy pad, an organic electroluminescent layer on the first electrode, a plurality of second electrodes on the organic electroluminescent layer within each of the pixel regions, and a plurality of connection electrodes electrically interconnecting the first substrate with the second substrate.