This study attempts to explain why the two major United Nations (U.N.) development programs for Africa in the 1980s and 1990s, UNPAAERD and UNNADAF, failed to promote economic and social development. Additionally, this study systematically analyzes the two development programs and identifies the internal and external causes of their failure by focusing on the processes of their formulation, adoption, implementation and evaluation within the U.N. General Assembly and discussing their formation and implementation within the context of the late 20th century world economic order.