The propagation and attenuation of shear waves in human skin is investigated over a frequency range of near zero to 1000 Hz. The results show that at frequencies below a few hundred Hz, shear waves propagate along the skin surface and thus provide information on the dynamic mechanical properties of the stratum corneum. The surface waves, however, are rapidly attenuated with increasing frequency so that at frequencies above about 500 Hz the energy is propagated only as bulk shear waves. Thus, at high frequencies the properties measured are those of the dermis.