This study examined the relationship between varying patterns of maternal employment, the use of child care, and the infant's establishment of a reciprocal, responsive relationship with the mother. Parental and non-parental caregivers were located within a family system to examine attachment theory within an ecological framework. The subjects were 147 Australian mothers, selected while pregnant with their first child, and interviewed about work and child care arrangements when the infants were 4 and 12 months of age to document the type, amount, and duration of parental and shared care experienced by each child in the first year of life. The results indicated that secure attachment was more likely to occur when mothers' employment and children's attendance at child care exceeded 10 hours per week. Maternal satisfaction with day care arrangements and maternal beliefs about the effects of employment on their child's well being are factors which are likely to moderate the impact of infant day care on the developing attachment relationship. (Contains 17 references.) (MOK)