The three‐dimensional simulation of the liquid crystal director deformation profile and the electric field distribution for the twisted nematic liquid crystal display has been carried out for the first time. The result gives us a complete understanding about liquid crystal deformation profile inside a pixel and the locus of the disclination line pair across the entire pixel area. This would not be possible in the case of the two‐dimensional (2D) simulation [A. Lien, Proceedings of the 10th International Display Research Conference (vde‐verlag gmbh, Berlin und Offenbach, 1990), p. 248; G. Haas, H. Wohler, M. W. Fritsch, and D. A. Mlynski, ibid., p. 252; A. Lien and R. A. John, IBM J. Res. Devel. 36, 51 (1992)], since the 2D simulation result is accurate only for the region which is far away from the corner area of a pixel.