This paper develops a framework for thinking about the policy challenge of scaling up small scale interventions, governmental and non-governmental, that address poverty reduction successfully. The framework sees scaling up as addressing different components of market failure, government failure and civil society failure. Viewed in this way, constraints to scaling up can be analyzed using a supply and demand framework on the one hand, a political economy framework on the other. The main conclusions are: (i) in scaling up the provision of basic social services, it is crucial to understand whether the binding constraint is on the supply side or the demand side, and (ii) successful expansion of successful civil society organizations has to manage in different ways constraints imposed by the market and by the government.