Rosalind Rabin, Frank de Charro, Agota Szende 1.1 Purpose of this booklet Governments and healthcare funders worldwide are making increasing use of economic evaluation to inform priority setting in health care. For various reasons, cost benefit analysis is usually rejected in favour of cost-effectiveness or cost-utility analyses, often involving the estimation of the incremental cost per Quality Adjusted Life Year (QALY) gained (Drummond et al, 2005). The estimation of QALYs gained requires valuations for all relevant health states on a scale anchored at 1 = Full health and 0 = Dead. The EQ-5D is widely used in this context and a number of value sets are available for all the health states generated by the EQ-5D descriptive system. These can be readily applied to health outcomes measured as EQ-5D profiles. EQ-5D has become one of the valuation approaches recommended by several reimbursement authorities and academic bodies in European countries (e.g. The Netherlands, Norway, Italy, Hungary, Poland, Portugal, UK), North America (e.g. Canada), and elsewhere (e.g. New Zealand). The EuroQol Group frequently receives requests for advice regarding EQ-5D valuation data. Those seeking to apply EQ-5D valuations in economic evaluation want to know about the availability of EQ-5D value sets and how they can obtain them. They also seek specific guidance about which of the available value sets they should use for their purposes.