This longitudinal panel study investigated predictors and outcomes of active engagement in career preparation among 349 Swiss adolescents from the beginning to the end of eighth grade. Latent variable structural equation modeling was applied. The results showed that engagement in terms of self- and environmental-exploration and active career planning related positively to interindividual increases in career decidedness and choice congruence. More perceived social support, early goal decidedness, and particular personality traits
predicted more engagement. Support and personality impacted outcomes only mediated through engagement. Early decidedness and congruence were significant predictors of their respective later levels. Implications for practice are presented.