Understanding positive youth development is crucial to inform prevention and intervention programs for behavioural and emotional problems, and to foster positive behaviour. This article reports the levels of positive school engagement, and family characteristics associated with engagement, in adolescents in Australia and the United States. It draws on the first wave of data collected in 2002 as part of the International Youth Development Study, a large cross-national study investigating the development of substance use and other behaviours in Australian and American school students. Brief information is included about the design and methodology of this study, and about the Social Development Model which underpins the research.