The increasing availability of Geographical Information Systems (GIS) in health organisations, together with the proliferation of spatially disaggregate data, has led to a number of studies that have been concerned with developing measures of access to health care services. The main aim of this paper is to review the use of GIS-based measures in exploring the relationship between geographic access, utilisation, quality and health outcomes. The varieties of approaches taken by researchers concerned with teasing out the relative importance of geographical factors that may influence access are examined. To date, in the absence of detailed data on health utilisation patterns, much of this research has focused on developing measures of potential accessibility. This paper then critically evaluates the situation with regard to the use of such measures in a broad range of accessibility studies. In particular, there has been less research to date that examines the relationship between such measures and health outcomes. In the final sections of the paper, I draw on the review to outline areas where a broader research agenda is needed, particularly in relation to more recent innovations in health care delivery.