To cite this article: P. Pathak (1982) The effects of defects on charged particle propagation in crystalline solids, Radiation Effects, 61:1-2, 1-46,The defects present in solid materials generally have important effects on the electronic, structural, thermal, mechanical and other properties of these solids; a knowledge of these is essential from any application viewpoint. Recently ion implantation has been recognized to be an extremely versatile technique for controlling any of these properties, either by doping desired foreign atoms in the solids or by producing a known and controlled amount of damage, or both. For a complete understanding and successful application of these phenomena, a thorough knowledge of the interaction of propagating charged particles with the defects, and of the resulting damage, is required. The present state of understanding and the work done so far on this subject are reviewed in this article and the need for and direction of further work are pointed out. ).Dr. Pathak's research interests include classical and quantum theories of ion-solid interactions in perfect and radiation damaged solids including energy loss theories, electronic properties of pure and defective solids and the theory of ion implantation and channeling radiation.