OBJECTIVES To index six countries on the basis of the risk they pose to pharmaceutical prices with regards to international reference pricing (IRP), from both an internal (how IRP is used by the country) and external (how other countries use this country for IRP) perspective.  METHODS Details on IRP methodologies were obtained from primary and secondary research. Achievable drug price levels in Bulgaria, France, Germany, Portugal and Romania were derived from these markets’ IRP formula and the relative drug price levels in their reference markets (based on existing literature). Furthermore, based on the IRP formulas and relative drug price levels of each of the markets referencing these five and the United Kingdom, the markets most likely influenced by the six were identified. This number of markets, the fraction of them representing major pharmaceutical markets, and the relative price levels in each of the six countries were assigned weightings to rank them by external risk.   RESULTS While Bulgaria, Portugal and Romania represent the greatest internal risk for pharmaceutical prices (i.e. greatest risk of obtaining a low price as a result of IRP), these markets fall into the low and moderate risk segments in the external risk index. Conversely, while France, Germany and the UK pose the greatest external risk (i.e. as a function of the number of significant markets referencing them), they fall into the low and moderate risk segments in the internal risk index. CONCLUSIONS The inversion seen between the two risk indices reflects a key aspect of the current IRP landscape. Namely, mature markets exert considerable influence on prices internationally, while their use of IRP exerts limited downward pressure on their own prices. Conversely, while IRP policy in emerging markets is more likely designed to secure the lowest possible prices, these markets carry less influence on prices internationally.