This dissertation examined an implementation gap through a case study on implementing a District Health System (DHS) in the Western Cape Province of South Africa between October 2001 and April 2006. The research project explored why this implementation gap existed and what could be learnt about public policy implementation from studying this implementation gap. The main data collection methods included interviews, public and other documents and observations on the public health system in the Western Cape Province. I argue that implementation gaps could be interpreted as a signal of policy change instead of implementation failure. The key finding is that the Provincial Government of the Western Cape shifted its intentions regarding DHS implementation. The initial intention was to decentralise primary health care services to a metropolitan municipality. The decision, which was actively implemented, however centralised these services within the provincial government and started the process of the provincialisation of personal primary health care services in the Western Cape Province. This dissertation contributes to public policy implementation and public policy process literatures. It demonstrates why policy change is an alternative interpretation of implementation gaps to implementation failure and how policy change occurs during implementation. Policy change and public policy implementation are commonly two separate research themes within Public Policy Studies. The persuasion framework developed through this research project is an analytical tool that may be applied in research on implementation processes to examine whether an implementation gap is signalling policy change. The central theoretical elements in this framework that link policy change and implementation processes are the interactive effects of ideas and interests and the role of argument as a persuading factor that leads to policy change. The dissertation emphasises the role of language in public policy processes and argument and persuasion were deemed important elements in public policy processes.