On the island of Ireland, there are two distinct and separate jurisdictions, namely the Republic of Ireland and Northern Ireland. Both were founded in 1922 with the former developing into an independent state while the latter still remains a part of the United Kingdom. The Irish Republic operates a primarily state-funded health care system, but an increasing input from private health insurance has arguably created a two-tier publicprivate system (Wren 2003). Northern Ireland’s health care system is primarily based on the UK’s National Health System (NHS) with some place-based variation (Jordan et. al. 2006). With the recent peace in Northern Ireland and the success of the ‘Celtic Tiger’ economy of the South, both governments are exploring joining up the economic and social structures across the whole island. Modelling access to health is one of the areas, which are currently being explored. Informally, there has been cross-border movement in the utilisation of health care for decades but there has been no strategic approach to modeling the implications of those flows. The need to plan in a cross-border setting is also explicitly stated in the new Republic of Ireland National Development Plan (NDP) for the period 2007-2013. With both governments being engaged in the restructuring of health care services, the Departments of Health in both countries were keen to explore the spatial dimension. As a result the potential of a GIS-based approach was identified as worthy of exploration. The National Centre for GeoComputation (NCG) at NUI Maynooth were approached and asked to develop an initial modelling of access to hospitals on an All-Ireland basis. A number of problems needed to be addressed related to the compatibility of spatial data, data merging in a cross-border environment and reliability issues. However each of these issues were likely to be an issue affecting the quality of the GIS analysis. The combined datasets were then used to examine the potential impact of policy-driven change both north and south of the border.