OBJECTIVES: A series of quality of life special interest groups were set up by ISPOR in 1999 to stimulate discussion and contribute to the advancement of science. The translation and cultural adaptation group has been working towards a set of Principles of Best Practice. METHODS: The approach reviews current practice, taking account of existing guidelines and theoretical perspectives. These perspectives have been evaluated with regard to the issues and challenges facing industry and the broader outcomes research community. A literature review was conducted in the first instance. All relevant papers and guidelines were reviewed and critiqued by the working group. The translation and cultural adaptation process was divided into its requisite components: forward translation and reconciliation, back translation, harmonisation, and testing/cognitive debriefing and each component was given to a member of the working group. The working group developed the principles of best practice document through taking a consensus of the guidelines and using their knowledge and experience to summarise and suggest the criteria for achieving success.. The draft document was then reviewed by all of the members of the QoL special interest groups at ISPOR. RESULTS: Eleven sets of guidelines were identified and critiqued. These included those from developers of generic measures such as the EORTC, EuroQol (EQ-5D), and IQOLA Groups. It also included guidelines developed by the Association of Test Publishers (ATP) and the World Health Organisation (WHO). The document produced by the group is tabular in format and includes four columns: name of step, key components, rationale, and risks of failing to complete the step. CONCLUSION: Further work will continue in order to expand the document to include discussion of a wide range of PROs and cultural adaptation of translations where an existing version exists but which has been developed for use in another culture.