We examined the mediational roles of multiple types of adolescents' emotional security in relations between multiple aspects of the interparental relationship and adolescents' mental health from ages 13 to 16 (N = 392). General marital quality, nonviolent parent conflict, and physical intimate partner violence independently predicted mental health. Security in the father-adolescent relationship, over and above security with the mother and security in regard to parent conflict, mediated the link from general marital quality to adolescents' mental health. With 2 exceptions, paths were stable for boys and girls, biological- and stepfathers, and Anglo- and Mexican Americans. The findings reveal the need to expand the traditional foci on parent conflict and relationships with mothers to include general marital quality and relationships with fathers.