OBJECTIVES: External Price Referencing (EPR) is used in many countries, but its scope and design vary substantially in different settings. The objective of this paper is twofold: first, to review the available evidence on the implementation of EPR across countries and, second, to assess whether differences in the design of the EPR policy may affect positively or negatively its impact within a country. METHODS: A systematic literature review using a keyword strategy was conducted both in the peer review and grey literature from 2000 to 2015 in order to record current and historical developments of EPR systems. RESULTS: