OBJECTIVES: The EQ-5D is one of the most widely used instruments to estimate utility values. The scoring system of the EQ-5D were developed from valuation studies, which estimate a scoring function for all EQ-5D health states based on the general population’s preference for a subset of health states. Due to the wide spread use of the EQ-5D a number of country-specific scoring systems have been developed. The objective of this study was to identify and compare all existing EQ-5D valuation studies and country-specific scoring systems. METHODS: An electronic search of MEDLINE, EMBASE, NHS EED, HEED and a search through the past proceedings of the Euroqol group up to September of 2010 was conducted to identify all EQ-5D preference elicitation studies. The review included a summary and comparison of study design, model estimation, study demographics and scoring function. RESULTS: After screening 2940 citations identified from the literature search, 33 elicitation studies that contained a unique scoring system were included for final review. The key areas of divergence between the studies include: differences in methodology used to directly value health (i.e. SG, TTO, etc.), the number of health states that were directly valued, the transformation of the directly valued health states, the statistical methods used to derive the scoring system, and the model variables included in the scoring system. CONCLUSIONS: Differences in methods do exist between population studies. Knowing the extent, at which the identified methodological differences can explain the variation, will help determine whether a global preference for health exists.