The quality of child–mother attachment relationships is context sensitive. Conflict and aggression in the marital relationship as well as aggressive discipline practices may diminish a child’s confidence in her or his mother as a secure base. We investigated whether physical aggression against the mother, exposure of the child to it, and use of aggressive physical discipline practices were related to attachment security. Forty-five preschoolers and their mothers from a nonclinical, middle-class population were studied. Security scores were obtained from observers’ descriptions of children’s behavior at home. Mothers reported on marital conflict, physical aggression from their spouse, exposure of the child to aggression, and use of physical discipline practices. Findings indicate that marital conflict, physical aggression, exposure of the child, and use of physical discipline are significantly and negatively associated with security. Regression analyses show that physical aggression contributed unique information to the prediction of security, and that physical discipline did not mediate the associations between physical aggression and child security. Clinical implications of the findings presented are discussed.