Background: Quality of life is a popular measure of outcomes and its widespread use has led to recent calls for a better understanding of the construct, emphasizing the need to build a substantial body of knowledge around what determines perceptions of life quality. Three widely reported and used conceptual principles are examined in this study. Methods: Self-ratings of life quality and three likely determinants at an individual level (stress), an interactional level (social support) and a community level (neighbourhood belonging) were used. The study involved two groups of young adults from an urban community, one identified as having an intellectual disability (ID). Results: Young adults with ID rated their satisfaction with health significantly higher and intimacy and community involvement lower than the comparison group. Social support emerged as the strongest predictor of life satisfaction across both groups. Conclusion: The conceptual principles of subjective quality of life provide a useful framework to discuss findings and to stimulate further research.