The World Health Organization (WHO) has undertaken a project to develop an instrument (the WHOQOL) for measuring quality of life. Quality of life is defined as an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns. It is a broad ranging concept affected in a complex way by the person's physical health, psychological state, level of independence, social relationships, and their relationship to salient features of their environment. The instrument will be developed in the framework of a collaborative project involving numerous centres in different cultural settings. In addition, it will have proven psychometric properties of validity, responsiveness and reliability and will be sensitive to the cultural setting in which it is applied, whilst maintaining comparability of scores across different cultural settings. This paper outlines the characteristics of the planned instrument and the study protocol governing work on its development. To date steps 1 through 5 have been completed and work is progressing on step 6. It is anticipated that the instrument will be available for piloting in July 1993 and a final version available for use in June 1994.