Aggressive behaviours in adolescence often originate in early development. This study tested three longitudinal pathways starting in early childhood, in a sample of 325 Belgian participants (162 girls) assessed every 1 or 2 years from birth through age 14. Structural equation models supported the "mother early dissatisfaction" pathway toward adolescent aggression, but neither the "cognitive functioning" nor the "early aggressive behaviour" pathway gained clear support. Mother's early dissatisfaction with her child was the starting point of a series of negative perceptions of the child, which predicted physical and social aggression in adolescence. Children's cognitive functioning and early aggression level were weakly correlated with mother's perceptions. This finding suggests that explaining normative development to parents may improve mothers' perceptions of their early experience as a mother, of their child, and of their subsequent interactions, which may reduce their child's future aggressive behaviours. (Contains 2 figures and 2 tables.)