PURPOSE:Body mass index (BMI) and physical activity (PA) affect health-related quality of life (HRQL); however, the long-term impact of youth BMI and PA on adult HRQL is unknown. We investigated the relationship of youth BMI and PA to adult HRQL 22 years later. METHODS:Subjects included 310 participants aged 7 to 18 in the 1981 Canada Fitness Survey, followed up in 2002-2004. The associations of youth BMI and leisure time PA to adult HRQL were examined, comparing to age- and sex-adjusted Canadian SF-36 norms. RESULTS:Bivariate analyses revealed positive associations between youth overweight and mental aspects of adult HRQL, but little association with physical aspects. In logistic regression adjusting for adult BMI and other covariates, overweight youth were 7 times more likely than healthy weight youth to score at/above the norm on both mental health (MH) and bodily pain, and almost 18 times more likely on the mental component score (MCS). Youth BMI was also positively associated with general health (GH), social functioning, and role emotional. Removing adult BMI from the models led to attenuated associations with mental HRQL and no association with GH. Longitudinal BMI status change was explored, and findings supported the main regression results. Youth PA was not associated with adult HRQL. CONCLUSIONS:Youth overweight conveyed a long-term positive impact on several aspects of adult HRQL, and this impact may be both direct and indirect through BMI change and the effect on adult BMI. Youth PA had no long-term impact on adult HRQL.