Analysis of high-resolution magnetic field data from the Pioneer Venus Orbiter spacecraft has shown that magnetic field rotations occur in association with the dayside ionopause of Venus. There is no evidence of a precursor to this rotation within the magnetosheath above the ionopause. This finding implies that the current system responsible for the field rotation is completely contained within the ionosphere, and therefore a return current must exist on the dayside below the ionopause. Further examination of the magnetic field data has revealed a secondary rotation at lower altitudes that we attribute to this return current. A large-scale dayside current system capable of reproducing these observations is described. ¿ 1997 American Geophysical Union