A brief survey is presented of a range of recent and current experiments in which medium energy ion scattering has been used to study the structure of metallic surfaces and near-surface interfaces. These include: surface alloy phases on elemental metal substrates in which the presence of interface and sub-surface stacking faults are investigated (Sb on Cu(1 1 1) and Ag(1 1 1)) and the amplitude and origin of surface layer rumpling are identified (Pb on Ni(111), Sn on Ni(1 1 0), Au and Mn on Cu(1 0 0)); near-surface composition and structure of a Pt25Rh75(111) alloy surface; the early stages of oxidation and oxide growth on Ru and Ni surfaces. (C) 2002 Elsevier Science B.V. All rights reserved.