Objective: To investigate associations of mental disor ders and physical illnesses during adolescence with qual ity of life (QOL) 17 years later. Design: The Children in the Community Study, a pro spective longitudinal investigation. Setting: Upstate New York. Participants: A community-based sample of mothers and their offspring were interviewed. Main Outcome Measures: Axis I disorders and Axis 11 personality disorders and physical illnesses were assessed by self-report and mother report in 1985-1986. Outcome indicators of QOL were assessed in 20012004. Results: Compared with participants without adolescent illness or disorder, those with a history of physical illness reported poorer physical health (mean difference [MD],-4.8); those with a history of an Axis I disorder reported poorer physical health (MD, -8.0) and more problematic social relationships (MD, -4.5); and those with a history of personality disorder reported poorer physical health (MD, -8.2), more problematic social relationships (MD, -5.0), lower psychological wellbeing (MD, -3.6), and more adversity within their environtriental context (MD, -4.6) in adulthood. Comorbid physical illness and mental disorder were associated with all 5 QOL domains (MD, -3.1 to -11.9). After adjusting for all demographic variables and comorbidity, associations remained between physical illness and poor physical health (effect size [ES], -0.33); an Axis I disorder and problematic social relationships (ES, -0.37); and personality disorder and problematic social relationships (ES, -0.36), low psychological well-being (ES, -0.23), impaired role function (ES,-0.24), and an adverse environmental context (ES,-0.50). Conclusions: Mental disorders may have more adverse long-term associations with QOL than do physical illnesses. Adolescent personality disorders may have a more adverse impact on adult QOL than do adolescent Axis I disorders.