There are no ready-made data on hospital outputs and inputs which would allow comprehensive international comparisons of hospital efficiency to be carried out. This paper, therefore, relies on selected evidence to compare hospital efficiency in a sub-set of OECD countries, based on three different approaches relying on, respectively: i) unit costs for standard hospital treatments; ii) overall efficiency levels in a set of paired countries; iii) within-country dispersion in individual hospital efficiency. The analysis suggests substantial cross-country differences in hospital performance. Although country coverage varies between the different approaches, making it difficult to assess the extent to which comparisons provide a consistent picture of national efficiency levels, cross-checks between the different indicator sets tend to support the robustness of the country rankings.