The changes of stainless steel surface roughness induced by neutralized ion-beam irradiation were investigated. Main roughness parameters (R_a, R_z, R_m, S_m) were measured using a high quality profilograph (Rank Taylor Hobson’s „Telysurf”). Ex situ and in situ observations of surface topography of ion-beam modified surfaces were performed by SEM. The influence of ion-beam incidence angle Q, ion dose and ion flux, as well as initial surface roughness and kind of target material on the resulting roughness was studied and some results are presented and discussed in this paper.