Using a cross-lagged panel design, this study examined the directionality of relations between parental psychological control and child relational aggression. Data were collected from a proportionally stratified sample of 600 Flemish 8- to 10-year-old children at 3 measurement points with 1-year intervals. Reciprocal effects were evident in mother-child dyads. Maternal psychological control was positively related to child relational aggression 1 year later, and child relational aggression was positively related to maternal psychological control 1 year later. The father-child dyads were best represented by unidirectional parent effects. Paternal psychological control was positively related to child relational aggression 1 year later. Surprisingly, these effects emerged only for relational aggression as indexed by mother and father reports and not for relational aggression as indexed by teacher and peer measures. (Contains 1 footnote, 5 tables and 1 figure.)