Ion-bombardment sputtering is used in combination with various analytical approaches in the surface analysis of solid samples. Although the advantages of sputter etching in this application far outweigh the disadvantages, there are several ways in which the sputter-etching process can cause interpretational difficulties. The characteristics of the sputter-etching process which are responsible for these difficulties include: (a) the fact that the elemental composition of a sputter-etched surface will in general be different from that of the bulk solid, (b) the tendency of certain materials to develop extensive microtopographical structure when they are subjected to ion bombardment, and (c) the fact that ion bombardment can cause motion of atoms in the sample by direct momentum transfer, cascade mixing, enhanced diffusion, or, in the case ofionized species, enhanced drift motion. A discussion of these effects wil be presented and an attempt will be made to assess their significance in the analysis of solid samples.