This paper describes the development of an add-on module for the WHOQOL measures of quality of life (QoL) for use with older adults. The add-on module, known as the WHOQOL-OLD, was derived following standard WHOQOL methodology. In the pilot phase of the study, 22 centres from around the world carried out focus groups with older adults, with carers, and with professionals working with older adults in order to identify gaps in the coverage of the WHOQOL-100 that were relevant for QoL in older adults. Items generated from the focus groups were then tested in over 7400 respondents from the centres, with items being tested and reduced using both classical and modern psychometric methods. These analyses indicated a further gap in the coverage of the items, so further items were generated that specifically assessed intimate relations in older adults. A field trial study was then carried out in a further approximately 5500 respondents, again with the use of both classical and modern psychometric methods. The outcome of this second round of data collection and analysis is a 24-item 6-facet module which can be used in conjunction with the WHOQOL-BREF or the WHOQOL-100 for assessment of QoL in older adults.