Studies examining relationships between demographic variables in a general population of psychiatric outpatients and quality of life (QOL), in which QOL was assessed according to current recommendations, have not been performed yet. The aim of this study was to examine one particular aspect of this relationship: the question to what extent QOL scores can be predicted by demographic variables. In a sample of adult Dutch psychiatric outpatients (n=495), demographics were recorded and the participants completed a questionnaire for measuring QOL (WHOQOL-100). The relationships of the demographic variables with the WHOQOL-100 domains Social Relationships and Environment, were stronger than those with the domains Physical Health and Psychological Health. The latter had only significant relationships with educational level and sick leave, which explain little of the variance of the concerning QOL domain. In general, the demographic characteristics used, explained only a relatively small part of the variance in QOL scores. An exception was sick leave, which, in participants with a job, explained an extensive part (27.4%) of the variance of scores on the domain Physical Health.