A pixel structure and an organic light emitting device including the pixel structure has at least one electronic material layer arranged between a lower electrode and an upper electrode. The pixel structure includes the lower electrode arranged in a desired pattern on a substrate and a bank covering the substrate on which the lower electrode is arranged, and defining an opening portion to expose at least a portion of the lower electrode. The area of the opening portion is greater than that of the exposed portion of the lower electrode. The pixel structure further includes an electronic material layer arranged in the opening portion and covering an upper surface of the lower electrode, and the upper electrode arranged on the electronic material layer.