The paper contributes to the debate on the political economy of implementation of propoor social policy. It argues for a broadening of the debate, which is dominated by technocratic arguments, emphasizing the lack of financial resources, technology or skills as the major barriers for effective implementation. Describing the dynamic interplay of 'formal' operational programme structures and 'informal' traditional institutions in delivering the CT-OVC - the largest and oldest cash transfer programme in Kenya - it argues for the need to look more closely into the local political economy as an important mediating arena for implementing social policies. Implementation is heavily contingent upon the local social, political and institutional context that influences and shapes its outcomes. These processes are highly dynamic and ambivalent evolving between 'formal' and 'informal' structures and institutions. They may change over time and place, challenging the implicit assumption that programmes are evenly implemented across geographic and political entities.