The words "Combinatorial Chemistry" have different meanings to different people, ranging from split and mix strategies to parallel synthesis using robots, and embracing the whole range of preparative chemistry from organic molecules, to catalyst ligands, and even inorganic solids. All of these activities have in common an attempt to expand the diversity of structure available to the chemist as well as the access to this diversity, permitting the discovery of new and valuable biological acid material properties. In this outstanding survey of combinatorial organic chemistry, the authors, Obrecht who has established a new combinatorial chemistry company calledPolyphor, and Villalgardo have brought together the literature, including that from 1998, and have concisely analysed the applications and achievements of this new field. This work will be of value to all chemists engaged in preparative work, both in industry and academe.