This research study delineates the role and spread of mass media and its impact on economic development of underdeveloped countries. Some definitions about mass communication are given, followed by a brief description of how the mass media in the countries of the world operate under four major theories. An examination is made of the economic development process itself, along with a listing of the contributions communication and the mass media have made to social and economic development. The problem of frustrations as created by the mass media is discussed, together with how mass media spread. Data are presented on the distribution of mass media, primarily for the underdeveloped countries of Brazil and the United Arab Republic. (Author/DB)