This is an introductory manual for Ion Assisted Deposition (IAD) procedures of thin films. It is addressed to researchers, post-graduates and even engineers with little or no experience in the techniques of thin film deposition. It reviews the basic concepts related to the interaction of low energy ion beams with materials. The main procedures used for IAD synthesis of thin films and the main effects of ion beam bombardment on growing films, such as densification, stress, mixing, surface flattening and changes in texture are critically discussed. A description of some of the applications of IAD methods and a review of the synthesis by IAD of diamond-like carbon and cubic-boron nitride complete the book.