Measuring the quality of life (QOL) of older persons can assist health professionals in achieving a number of important objectives. These include assessing the effects of illness and treatment, identifying need for support services, and developing health enhancing environments. Most QOL models focus unduly on illness and disability, define QOL too narrowly, and do not consider aspects of personal control and potential opportunities for change. A new model of QOL with associated instrumentation, the Quality of Life Profile: Seniors Version (QOLPSV), is described. Administration of the QOLPSV to 205 older persons in Ontario, Canada found it to be reliable and valid. Limitations of the instrument are presented and potential uses explored.