Current interest in the new economic growth theory, linked with the development of new, innovative methods of measurement, has resurrected interest in spatial economic convergence. The primary objective of this paper is to examine the extent that regional economies seem to be converging or diverging. It explores the expanding theoretical literature in the field and examines the growing body of empirical evidence that has emerged in recent years not only in the U.S. but also internationally. The paper is retrospective but also embraces new findings relating to the United Kingdom and the U.S., putting particular emphasis on long- and short-term indicators of economic convergence.