A caster adapter is used for adapting a plurality of caster wheels onto a hand truck of the type having a backing frame extending longitudinally between a handle portion at a top end and a toe plate at a bottom end. The adapter includes a frame assembly mounting the caster wheel assemblies thereon for rolling movement along a ground surface. A pair of pivot couplings on the frame assembly pivotally couple the frame assembly on the backing frame of the hand truck for pivotal movement about a tilt axis which is parallel to the toe plate and proximate to the bottom end of the backing frame.