The average ultimate tensile strength, loaded in the direction of the long axis, of the compact bone of 15 specimens taken from the parietal bone of adult human embalmed cadavers was 10,230 lb/in.² (6,030–15,800). Compression tests were then made on smaller specimens cut from the original tensile specimens. The average ultimate compressive strength of the compacta of 69 specimens, loaded in the direction of the long axis of the original tensile specimens, was 22,080 lb/in.² (12,400–47,800) but the 56 specimens, loaded perpendicular to the original long axis, had an average compressive strength of 24,280 lb/in.² (4,500–46,900). The average tensile strength of the specimens from the right parietal was 12% greater than that of the specimens from the left bone. The average compressive strength, loaded lengthwise, of the specimens from the right and left parietal bones was practically identical, but the compressive strength, when loaded perpendicular to the long axis of the specimens, from the left parietal was 16% greater than the average strength of the specimens from the right side. The 23 specimens of spongy bone (diploe) tested had an average compressive strength of 3,640 lb/in.² (1700–5770). The average tensile strength of parietal compacta is less than that of compacta from long bones but the compressive strength, loaded both lengthwise and crosswise, is similar to that of compacta of other bones. However, the compressive strength of the parietal compacta exceeds its tensile strength by a greater percentage than is true of compacta from long bones. The compressive strength of the diploe is approximately the same as that of femoral spongiosa.