We present a study of the shape, size, and spatial orientation of superclusters of galaxies. Approximating superclusters by triaxial ellipsoids we show that superclusters are flattened, triaxial objects. We find that there are no spherical superclusters. The sizes of superclusters grow with their richness: the median semi-major axis of rich and poor superclusters (having >=8 and <8 member clusters) is 42 and 31h^-1^Mpc, respectively. Similarly, the median semi-minor axis is 12 and 5h^-1^Mpc for rich and poor superclusters. The spatial orientation of superclusters, as determined from the axes of the ellipsoids, is nearly random. We do not detect any preferable orientation of superclusters, neither with respect to the line of sight, nor relative to some other outstanding feature in the large scale structure, nor with respect to the directions of principal axes of adjacent superclusters.