The sputtering yields, as well as the angular and energy distributions of the sputtered atoms can be modified by a monolayer of adsorbed atoms. The magnitude of such effects have been estimated with the help of a computer simulation (MARLOWE) in the specific case of a copper single crystal (100) face covered with a p(2 × 2) monolayer of cesium and bombarded with a 10 keV Ne beam. For three different orientations of this beam, the mean radii of the cascade range and the sputtering yields are calculated with. and without, cesium coverage. It has been found that the main effect of cesium coverage lies in the angular distributions of the sputtered particles.