Accurate calculations for the correction of the Rutherford scattering cross section are presented, based on the potentials obtained from the Dirac-Fock electron distributions. The calculations have been tested against relative4He back- scattering measurements in Al, Cu, Ag, and Au in the energy range 200–2000 keV. Complete consistency has been found to within experimental error (0.5–1%). At 170° scattering angle, thecorrections found were in A10.1–1.5%, in Cu 0.5–4%, in Ag 0.7–8%:, and in Au 1.7–15%.