This longitudinal study examined how adolescents' perceptions of attachment security with parents relate to their process of choosing a major in higher education. The participants were 281 students who were investigated at the beginning, middle, and end of Grade 12. Findings showed that higher perceived security with mother, but not with father, predicted higher levels of coping with the career decisional tasks of orientation, broad and in-depth environmental exploration, and self-exploration in the future. However, perceived security did not relate to the degree of change in decisional tasks during Grade 12. Finally, results suggested that the association between perceived security with mother and the decisional tasks of orientation, broad and in-depth environmental exploration, and self-exploration was mediated by adolescents' career decision-making self-efficacy.