Lattice disorder produced by ion implantation of CdS crystals with Bi+, Kr+, Ar+and Ne+has been studied using RBS/Channeling and Transmission Electron Microscopy (TEM). Channeling measurements of the damage, as represented by an apparent number of displaced atoms, ND, obtained from the surface peak and by the change in the dechanneling, level, ΔXmin, behind the surface peaks, have been studied as a function of channeling direction (c- anda-axis), He+beam energy (0.8–2.8 MeV), implant and analysis temperature (50 K and 300 K). The channeling measurements are consistent with the TEM observations that the damage is primarily in the form of interstitial type dislocation loops which predominantly lie with a Burgers vector parallel to thea-axis. Both techniques confirm that implantation does not produce an amorphous layer in CdS.