The current study examined direct and indirect influences of romantic attachment processes, marital adjustment, and the coparenting relationship on family functioning. Data was collected from a community sample of 86 heterosexual couples with a child aged eight to eleven living in the home. Both spouses completed a demographic questionnaire, the Experiences in Close Relationships Scale, the Dyadic Adjustment Scale, the Coparenting Scale, and the Self-Report Family Inventory as part of a larger study on family processes in middle childhood. Data analysis included multilevel modeling, utilizing the actor-partner interdependence model. Results indicated that marital adjustment mediated the association between attachment processes and family functioning, suggesting that a healthy marital relationship is an important variable that helps explain links between attachment security and the family functioning. Findings also highlighted the benefit of conceptualizing adult romantic attachment, marital, and coparental subsystems within a systemic framework.