A critical issue in decentralisation is the assignment of services to sub-national governments. This article examines normative arguments, legislated models and actual experiences of Sub-Saharan service assignment in two key service sectors, primary health care and rural roads, each of which is a common target for decentralisation efforts and has substantially different characteristics. In analysing intergovernmental provision and production arrangements and the way in which different service components are organised in these sectors, it is apparent that legislated models of decentralisation are largely informed by normative theory. In both sectors, however, a disjoint is evident between what governments decentralise in a formal sense (i.e. in the law) and what they decentralise in an actual sense. This disjoint can be partially explained by normative arguments about the limits to decentralisation, for example, spillovers and economies of scale, but also result from the influence of factors such as intergovernmental and bureaucratic politics, local level capacity constraints and particular production issues associated with each service.