Taking an ecological systems perspective, early parent-child relationships can be affected by interactions between many systems where some are more proximally linked to the child than others. For example, socioeconomic status is generally considered a more distal factor but has been found to be related to maternal warmth and child aggression. However, research on socioeconomic status and infant socio-emotional functioning is scant and inconsistent. Other systems such as marital functioning can also affect the parent-child attachment relationships, perhaps indirectly or directly, such that parents who are unhappy in their marriage may withdraw from their child and negatively affect the parent-child relationship. The current study aimed to examine the role of various ecological systems in early infancy – parental resources, marital functioning, and parental sensitivity and involvement-on later infant attachment security with mothers and fathers. Both mediation and moderation models were tested. Findings suggested greater support for moderating than mediating processes. In addition, results indicated that both distal and proximal factors predicted infants‘ attachment security with both parents. More specifically, parental resources, parental sensitivity, and involvement predicted infants‘ attachment security with both parents. Marital conflict served as a moderating factor in infants‘ attachment security with mothers, whereas marital satisfaction served as a moderating factor in infants‘ attachment security with fathers. Implications for future studies and interventions are discussed.