The distributions in angle an d energy for charged particles emitted from polycrystalline and crystalline platinum (100 face) bombarded with ions of hydrogen, nitrogen and argon, have been m easured, in continuation of previous work (Cawthron, Cotterell & Oliphant 1969, part I and II). Hydrogenions incident on polycrystalline platinum , with energy of the order of 10 keV, give distributions with angle of incidence, α, and angle of scattering, θ, in general accord with what might be expected, but the heavier ions show marked differences, probably due to some sputtered atom s escaping with electric charge. With the crystalline target, where effects of channelling were observed in the angular distribution of emitted charged particles, these were accompanied by marked changes in the energy distribution of these scattered particles.