Investigators at the Centers for Disease Control and Prevention in the US have developed a brief survey tool to measure health-related quality of life (HRQOL-4). In order to support use of such tools in surveillance, it is important to assess their validity in different groups. Subjects were 926 non-institutionalized men and women (age > or = 65 years) who completed a health exam and questionnaire. Results indicated that physical and mental health and physical activity limitation were each related to self-perceived health. Compared with subjects who reported excellent health, those with poor self-rated health reported a more than 17-fold increase in the number of unhealthy days in the previous 30. While responses to questions addressing psychosocial factors were most consistently associated with the HRQOL item relating to mental health, responses to health and health behaviour questions were more consistently associated with items related to physical health. This study demonstrated that the HRQOL-4 is not only accepted by older adults in a self-administered format, but also stands up to tests of its validity.