This paper examines the relevance and cost-effectiveness of the use of mass media for spreading education and the dissemination of information needed to sustain growth and technological progress in developing countries. An overview of experiments with the use of radio and television for educational purposes provides brief descriptions of distance education projects in the USSR, the United Kingdom, Niger, Honduras, Rwanda, Nicaragua, the United States, India, Australia, and Malaysia, and notes related activities in other countries. Discussion of the economics of distance education focuses on issues raised by case studies on the cost-effectiveness of distance education in various countries. Prospects and issues in the field are then discussed in the context of: (1) primary and secondary education; (2) teacher education; (3) education management and administration; (4) tertiary education; and (5) nonformal education. A brief review of the Asian Development Bank's involvement in distance education concludes this paper. Sources of additional information on the projects described and the case studies cited are indicated in footnotes. (MES)