Advocates of pluralist, competitive politics have regarded decentralization as a device for deepening democracy or for prying closed systems open and to give interest groups space in which to organize, compete and otherwise assert themselves. Some politicians in central governments see it as a means of delegating expensive tasks to others lower down. From a political economy perspective, this study examines the origins of the current wave of decentralizations in less-developed countries and its implications, especially its promise and limitations for rural development. It is based mainly on empirical evidence drawn from experiments with decentralization in a large number of countries. The paper is divided into six parts. Part I defines terms to show that the word 'decentralization' can mean many different things. Part II examines why some political regimes have often tended not to decentralize even when all indicators support the need for it. Part III seeks to explain the tendency of many regimes during the early 1980s to decentralize. Part IV examines the encounter between decentralized institutions and how they operate within their state-society and political milieu. Part V discusses the advantages and disadvantages of decentralization. Part VI assesses the promise of decentralization for rural development.