Since the beginnings of development assistance to Third World countries during the post-World War II period, there have been some philosophical changes in the theory and practice of development aid programmes. Western development aid ( i.e., of the United States and West European countries), can be classified into two main conceptual types. These include economic growth as development objective and economic growth with an increased quality of life as development objective. The first two decades of development assistance 1950–1970 focused on economic growth objectives with increased production. The period, 1970–1980 concentrated on redistributive measures to improve the quality of life of the rural poor, the provision of basic needs, creation of employment opportunities, and the implementation of policy measures to reduce relative inequality and absolute poverty. The main purpose of this article is to discuss the changes in the theory and practice of Western aid programmes in Third World countries from 1945–1979. We will look into the underlying international causes that contributed to these changes. We will also review the evolution of aid to Third World countries for the last thirty years by examing the economic, political and social background for the changes in development assistance from urban to rural development programmes and from an emphasis in increasing production to that of redistribution with growth. These problems are discussed in the hight of their relevance for policy-onented rescoorch in Third World Comtnes.