Introduction: This longitudinal study investigated whether and how parental conflicts contributed to adolescents' endorsement of materialistic values. Method: Two hundred and fourteen Chinese adolescents in Hong Kong (102 boys; mean age = 16.52 years) completed a set of questionnaires including materialism, emotional insecurity, parental conflict behaviour, and perceptions of parents (warmth, autonomy, and involvement). Results: Consistent with the psychological insecurity hypothesis and the emotional security theory, emotional insecurity mediated the connection between parental conflict behaviour and adolescents' materialism. Adolescents who had their parents dealing with their conflicts in destructive ways reported higher levels of emotional insecurity, which was in turn associated with higher levels of materialism. By contrast, adolescents who had their parents dealing with their conflicts constructively reported lower levels of emotional insecurity, which was linked to lower levels of materialism. Conclusion: Parental conflict behaviour contributes to adolescents' materialism through its influence on emotional insecurity.