This paper briefly examines how social capital affects overall economic growth processes and individual firm development, both positively and negatively, in low- and middle-income countries. The paper discusses how the concept of social capital is related to simple economic growth models and to the analysis of economic networks these countries. The degree to which social capital can substitute for or complement other forms of capital investment is examined. The paper concludes with suggestions for future research and policy analysis by agricultural economists in this area. Keywords: social capital, economic development, marketing networks