This article responds to recent calls for a focus on successful development in young people and examination of its developmental precursors, in order to identify potentially modifiable targets for interventions. The current study examined child and adolescent precursors of positive functioning in emerging adulthood, including individual characteristics, relationship factors, and connections to the community, using a multidimensional positive development measure at 19-20 years. The sample consisted of 511 males and 647 females who were participants in the Australian Temperament Project, a population based longitudinal study that has followed young people's psychosocial adjustment from infancy to early adulthood. Higher levels of positive development in emerging adulthood were associated with stronger family and peer relationships, better adjustment to the school setting, higher family socioeconomic status, and better emotional control. Some significant gender differences were observed, with emotional control, family relationships, and community orientation all being stronger predictors of males' than of females' positive development. The findings provide possible targets for child and adolescent interventions to promote positive development in early adulthood.