The last few years have seen great progress in the understanding of nuclei far from stability, i.e. nuclei with a composition that differs radically from that of the stable nuclei that we encounter in Nature. It has become clear that the study of exotic nuclear species reveals many new phenomena, which may make us go back, armed with new insight, to more familiar nuclear systems. The proceedings at the 4th course of the International School of Heavy Ion Physics — Exotic Nuclei, containing the lectures and seminars by world specialists in the field, cover some of the central themes of the physics of exotic nuclei which lie at the forefront of nuclear research.
