There is growing interest in the social sciences in the concept of social capital and the role it plays in facilitating collaborative and collective actions. Within political science, it is the work of Robert Putnam which has dominated social capital research. This paper argues that the ‘Putnam-school’ approach is lacking in two main respects. First, the role played by public authorities in the creation of social capital is neglected. Second, the implications for governance cannot simply be read off from associational activity and ‘stocks’ of social capital. The concept of the political opportunity structure is offered and adapted to develop a framework for social capital analysis. Original empirical material from Birmingham is drawn upon and compared to earlier studies of the city in order to support and illustrate the arguments of the paper.