In response to European regulators' concern about the methodology followed to translate and achieve cultural adaptation of Health-related Quality of Life (HRQL) instruments (i.e. the process of adapting a measure from a source to a target language), the ERIQA Group has integrated the development of regulators-targeted guidance documents for cross-cultural adaptation into their programme. The first step in collaboration with Mapi Research Institute has been to investigate current guidelines. OBJECTIVES: To identify and analyse the methods used for cultural adaptation of HRQL instruments. METHODS: Medline and Embase were searched using the keywords "quality of life", "questionnaires", "health status indicators" which were matched with "translating" and "cross-cultural comparison". Papers published between January 1966 and April 2001 were taken into consideration. 173 references were identified. Mapi Research Institute's database was searched using "translation issues", "cross-cultural comparison", and "cross-cultural research", with 236 references as a result. 409 abstracts were reviewed. Inclusion criteria were: 1) the paper should propose guidelines/recommendations or 2) it should review and analyse methods. RESULTS: 32 papers met with the inclusion criteria. 14 sets of guidelines were identified. A lack of consensus emerged about: a) the terminology qualifying the process of adapting a HRQL instrument from source to target language, and b) the scope covered by this terminology. Similarities included multiple forward translations, reconciliation sessions, and some form of back-translations. Differences appeared in the importance given to back-translation, forms of panel testing, and translators' recruitment criteria. Few articles compared methodologies. CONCLUSION: This review shows disparity in definitions and methods. Further investigations may be needed in order to explore empirical evidence of the methods' effectiveness, and propose recommendations for regulators.