Advancing the process-oriented study of links between interparental discord and child adjustment, 2 multimethod prospective tests of emotional security as an explanatory mechanism are reported. On the basis of community samples, with waves spaced 2 years apart, Study 1 (113 boys and 113 girls, ages 9–18) identified emotional security as a mediator in a 2-wave test, whereas Study 2 (105 boys and 127 girls, ages 5–7) indicated emotional security as an intervening mechanism in a 3-wave test. Relations between discord and emotional security increased as children moved into adolescence in Study 1. Emotional security was identified as an explanatory mechanism for both internalizing and externalizing problems in children.