Carbon has always been a unique and intriguing material from a funda­ mental standpoint and, at the same time, a material with many technological uses. Carbon-based materials, diamond, graphite and their many deriva­ tives, have attracted much attention in recent years for many reasons. Ion implantation, which has proven to be most useful in modifying the near­ surface properties of many kinds of materials, in particular semiconductors, has also been applied to carbon-based materials. This has yielded, mainly in the last decade, many scientifically interesting and technologically impor­ tant results. Reports on these studies have been published in a wide variety of journals and topical conferences, which often have little disciplinary overlap, and which often address very different audiences. The need for a review to cover in an integrated way the various diverse aspects of the field has become increasingly obvious. Such a review should allow the reader to get an overview of the research that has been done thus far, to gain an ap­ preciation of the common features in the response of the various carbon to ion impact, and to become aware of current research oppor­ allotropes tunities and unresolved questions waiting to be addressed. Realizing this, and having ourselves both contributed to the field, we decided to write a review paper summarizing the experimental and theoretical status of ion­ implantation into diamond, graphite and related materials.