The aim of this study was twofold: a) to test the mediation role of attachment between parenting practices and aggressiveness, and b) to clarify the differential role of mothers and fathers with regard to aggressiveness. A total of 554 adolescents (330 girls and 224 boys), ages ranging between 16 and 19, completed measures of mothers' and fathers' parenting practices, attachment to mother and to father, and aggressiveness. Acceptance/involvement of each parent positively predicted an adolescent's attachment to that parent, and coercion/imposition negatively predicted attachment to a lesser extent. Using structural equation modeling, a full mediation model provided the most parsimonious explanation for the data. With attachment in the model, the paths between the two parenting practices and aggressiveness were minor and statistically non-significant. Only attachment to the father, was predictive of adolescents' aggressiveness. Results are discussed in the light of the importance of the father-son/daughter relationship in adolescence. (Contains 3 figures and 2 tables.)