The WHOQOL-OLD is an international cooperation of 22 research centres under the sponsorship of the WHO for the development of an intercultural instrument for the assessment of quality of life in old age. This article outlines the fundamentals of the WHOQOL-OLD project and presents the current results of the empirical investigations for the German version of WHOQOL-OLD. Since it is an essential aspect of the WHOQOL project to include both the perspective of medical experts and that of lay persons, focus groups were conducted with lay people and health professionals at the outset of the project. The aim of these focus group discussions was to test the dimensional structure of the quality of life concept for elderly adults and to develop facet definitions. The results of the focus groups showed that elderly people associate social, physical as well as environment-related aspects with the term quality of life. The results of the international focus groups are largely identical with those of the German focus groups.