Exact Image Theory, previously introduced to electromagnetic field problems involving arbitrary sources and planar interfaces of simple isotropic media, is extended to vertical electric and/or magnetic sources above a planar interface of a chiral medium with small chirality. The resulting image functions are shown to be generalizations of those encountered in the simple isotropic case and coincide with previously obtained quasistatic results. Far-field approximation of the image method is shown to lead to a simple reflection coefficient image principle.