OBJECTIVE: Family conflict is associated with low self-control in adolescence. Thus far research about the direction of this association is inconclusive. In this study, we sort out whether this association reflects a causal effect or whether it is explained by a common underlying cause, including genetic factors. METHOD: In twin data, we fitted a series of causal models, and compared models for the association of family conflict and self-control including reciprocal causation, unidirectional causation from family conflict to low self-control, unidirectional causation from low self-control to family conflict, and common genetic susceptibility. We included data of a large sample of twins aged 14 (N=9,173), all enrolled in the Netherlands Twin Register. RESULTS: The results suggested a unidirectional pathway model where family conflict leads to low self-control in adolescence, with genetic factors also playing a role in explaining the association. CONCLUSION: Adolescents experiencing family conflict are at risk to show hampered self-control capacities, with family conflict being a robust predictor of low self-control through common genetic factors but also through direct causal influences.