This paper is a review of the principles, techniques, and some recent applications of ion scattering for surface and surface layer analysis. Three energy ranges, loosely defined as high (1–2 MeV), medium (100–400 keV), and low (0.5–10 keV) are discussed separately. We have not attempted a comprehensive review of such a large and rapidly growing field. Examples are taken mainly from experiments with which the authors are familiar. A summary table at the end shows the diversity of problems to which ion scattering has been applied.