A stereoscopic image display apparatus having a low image data input rate, in which the required capacity of a memory is reduced without causing flicker and ghosts. In the invention, right and left parallax image data is compressed, the compressed image data is stored in a frame memory, each of compressed image data for a right eye and compressed image data for a left eye, corresponding to the same display gate line, is read and decoded, line by line, and parallax image data for the right and left eyes for one frame are displayed multiple times, as alternating right and left fields, within one frame period.