Career exploration encompasses the active reflection of personal interests, abilities, and values as well as the exploration of possibilities in the world of work. As such, it is a crucial developmental task in adolescence which lays the foundation for informed career decision-making, self-determination, and achievement of a vocational identity. The chapter describes a longitudinal panel study with 330 Swiss adolescents in eighth grade investigating antecedents of active career exploration, and its effect on development of confidence in terms of self-efficacy beliefs. Based on Motivational Systems Theory the study investigated the four predictors-emotional stability, active goal orientation, capability beliefs, and perceived social support. Data were analyzed with latent variable structural equation modeling. The four assessed predictors explained 41% variance in career exploration, with more active goal orientation, more social support, and less emotional stability being significant predictors. More active exploration led to an increase in personal confidence over time supporting the importance of active career exploration for positive youth development. The positive effect of exploration on confidence development was independent of a student’s emotional stability or social support. Gender differences in these findings and implications for career development theory and practice are discussed.