Background: Study older adults' quality of life is becoming increasingly important in the assessment, quality improvement and allocation of health and social care service. The purpose of this study was to enhance knowledge on the relationship between modifiable (psychological variables) and nonmodifiable variables (sociodemographic), and quality of life in elderly, in order to inform social, health and education policies.Methods: This is a cross-sectional study, including 604 older adults from general community. 63.6% of the sample was composed by female gender with a mean age of 71.6(SD=4.81). Participants completed the following instruments: Barthel Index to assess functionality; Satisfaction with Social Support Scale to assess social support; The Spiritual and Religious Attitudes in Dealing with Illness to assess spirituality and Short Form Health Survey 36, to assess mental and physical quality of life. Results: A path analysis model was performed where the presence of a chronic disease, age and functionality has a direct effect on physical quality of life and spirituality had a direct effect on mental quality of life. Social support mediated the relationship between functionality and mental quality of life, and in turn, functionality mediated the relationship between age and physical quality of life. Conclusions: Results reinforce the effect of age and chronic disease as non-modifiable variables as well as functionality, spirituality and satisfaction with social support as modifiable variables, in the quality of life of older people. Social support, health and education programs in the community should be promoted in order to improve quality of life in this population. Strategies to promote functionality and enhance the social support network, especially in the elder with chronic illness, should be a priority.