This study tested the developmental trajectories of career maturity (CM) and parental attachment (PA), the longitudinal influence of both, and gender as a moderator. Findings showed developmental progressions in adolescents' PA and CM over 4 years. The change in PA was positively related to the developmental change in CM. For gender, there was a statistically significant difference in the initial status of CM and PA but no significant difference in developmental change. This study verified the longitudinal influence of PA on CM and showed that the cross-sectional effect of predictors on CM needs to be distinguished from the longitudinal effect in future studies.