An organic electroluminescent display device includes a first substrate, a second substrate spaced apart from and facing the first substrate to form a space therebetween, an array element on an inner surface of the first substrate, an organic electroluminescent diode on an inner surface of the second substrate, a seal pattern along a peripheral portion between the first and second substrates, and a connection pattern electrically interconnecting the array element and the organic electroluminescent diode, wherein a pressure within the space between the first and second substrates is lower than an ambient atmospheric pressure.