This paper deals with the continuation of the work described in a previous paper (He, Ne, Ar and N₂) see ibid., vol.9, no.2, p.185 (1976) and is an extension to the heavier noble gases, Kr and Xe. Relative differential cross sections for electrons elastically scattered by Kr and Xe were measured at impact energies between 100 and 3000 eV and at scattering angles between 5 and 55 degrees. The relative cross sections were put on an absolute scale by a procedure using the apparatus calibration factor derived from absolute measurement on N₂. The results are discussed in comparison with those of other authors. At the same time it was possible to derive apparent polarizabilities from the measured data.