The objective of the study presented herein is to develop an empirical predictive relationship for permanent relative displacements for use in assessing the seismic stability of slopes, dams, and/or embankments subjected to active shallow crustal earthquake motions. A total of 330 horizontal motions, recorded at rock sites during 29 earthquakes in active shallow crustal regions (e.g., western North America: WNA), were used in this study. For each motion, the permanent relative displacements were computed using the Newmark sliding block procedure for a suite of yield-accelerations: 0.01, 0.05, 0.10, and 0.20 g. The predictive relationship proposed herein was derived by performing separate regression analyses for each yield-acceleration. This allows the relationship to be simply formulated in terms of ground motion characteristic parameters, independent of yield-acceleration (ky), and results in lower standard deviations than those for relations developed by regressing all the data in a single analysis. The non-linear mixed-effects technique was used to regress the relative displacement data as functions of maximum ground accelerations and velocities (Amax and Vmax, respectively). The median permanent relative displacements predicted for WNA rock motions decreases with increasing ky/Amax but increases with increasing Vmax. Also, the rate of decrease in displacement with respect to ky/Amax varies as a function of ky