For the past forty years educational investment in the countries of the Third World has been high on the political agenda. Whereas, however, economists and educational theorists in the 1950s and 1960s had a relatively simplistic understanding of the linkages between education and economic development, the complexities of the inter-relationship have gradually become better known and documented. Today there is far less certainty. This paper seeks to trace the major thrusts in educational development during this time, partly through a study of the literature, partly through a study of some of the experiments, and failures, that have taken place. It assesses the achievements and the ongoing problems, while at the same time looking at some of the lessons that have been learnt. It ends by identifying a number of ongoing issues likely to dominate the 1990s.