Three-dimensional trajectory calculations are used to investigate the effects of inertial drifts due to magnetic field orientation changes in the dayside magnetosphere. It is demonstrated that the well-known field line curvature drift and that due to curvature of the E¿B path act in very distinct manners. Though negligible at low altitudes, it is shown that the latter drift may be of importance in regions adjacent to the frontside magnetopause. In these regions, it yields substantial parallel energization of low-energy ions such as those originating from the high-latitude ionosphere. Because this acceleration occurs prior to entry into the nightside magnetosphere, these ions are subsequently less subjected to large-scale plasma convection and populate more distant sectors of the magnetotail. On such basis, the rarely considered drift due to curvature of the E¿B path appears as an important feature of plasma transport in the magnetospheric flanks. ¿ American Geophysical Union 1994