This book is based on contributions to the NATO Advanced Research Workshop on Recombination of Atomic Ions. This was held at the Slieve Donard Hotel in Newcastle, Northern Ireland, between 6 and 9 October 1991 and attracted 35 participants from 5 countries. The book is inter.~ed to serve as an in-depth review of work to this date on the subject of recombination of atomic ions both in collision with free electrons and with atoms. It contains contributions from almost all groups which have made significant contributions in this area during the last decade. In addition, a synopsis of the discussion session following each of the main subject areas is presented. The material is organized into several themes; an overview of the subject area, theoretical aspects of recombination, experimental measurements of electron-ion recombination and experimental measurement.s of recombination in ion-atom collisions. We would like to acknowledge the sponsorship of the NATO Scientific Affairs Division. We would like to thank the Northern Ireland Tourist Board and the Queen's University of Belfast for providing some additional funding. Finally we would like to thank all the contributors to these proceedings for their efforts in preparing the manuscripts and their assistance in the editing process.