Physical data are presented from measurements taken on the heads of 19 male and two female unembalmed cadavers. The coordinate reference system for all locations and directions of the data is that described by Thomas (1972), based on four anatomical landmarks located on the skin over the left and right infraorbital notches at the superior edge of the left and right external auditory meati. These four points are assumed conplanar (Frankfort Plane) with the origin at the midpoint of the left and right infraorbital notches. The X-Z plane is considered the mid-sagittal plane. The data show that the center of gravity is located almost exactly in the X-Z plane. The principal moments of inertia vary from 136 to 274 kgm. sq. cm. about the X' axis, from 167 to 298 kgm. sq. cm. about the Y' axis, and from 110 to 198 kgm. sq. cm. about the Z' axis. The radii of gyration (mean) for the X', Y', and Z' axes are 6.89 cm., 7.18 cm., and 5.85cm., respectively. The variation of head weights accounts for about two-thirds of the variations of the principal moments.