Early attachment has been commonly hypothesized to predict children's future developmental outcomes, and robust evidence relying on assessments of single caregiver-child attachment patterns has corroborated this hypothesis. Nevertheless, most often children are raised by multiple caregivers, and they tend to form attachment bonds with more than one of them. In this paper, we briefly describe the conceptual and empirical roots underlying the notion of attachment networks to multiple caregivers. We detail potential reasons for research focusing on a single caregiver (most often mothers, but recently also fathers) and the historical attempts to establish a more ecologically valid assessment of attachment to multiple caregivers. Finally, we describe a recently developed organizational framework that includes testable models on which future research may rely for assessing the predictive power of attachment networks to multiple caregivers on children's developmental outcomes.