Although social capital is a potentially important asset for poverty reduction in developing economies, there has been little analysis of factors affecting its formation in developing countries such as Uganda. This paper analyzes what influences households to join local organizations and the intensity of social networks in central Uganda. Social networks were disaggregated by major activity to gain insight into household access, and the interaction between local organizations and social networks was examined. Probit and ordered probit models were estimated to identify what led households to participate in organizations and the intensity of participation. A negative binomial model was applied to analyze the household intensity of social networks. The findings revealed that household characteristics and aspects of village homogeneity influence various dimensions of social capital and that there was positive interaction between the social capital generated by local organizations and that derived from social networks. The study has important policy implications for agricultural extension programs that use a group based approach.